Based on the comparison between the properties of the unknown elements and those of known elements, the elements are alkali metals.
The unknown elements are sodium and potassium.
What are the properties of alkali metals?Alkali metals exhibit metal properties such as strong thermal and electrical conductivity, luster, ductility, and malleability. In the outermost shell of each atom of an alkali metal, there is just one electron. Compared to those in inner shells, this valence electron is significantly more loosely bonded.
Other properties of the alkali earth metals are:
Stored in a mineral oil solution.Low melting points.Low densitiesLow electronegativity.Low ionization energy.Learn more about alkali metals at: https://brainly.com/question/30391109
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Please help Quick I don't get it. and quick I got a time limit till tomorrow.
Dichotomous keys for the above can be:
Organism has legs only.... Organism has both legs and wings?They possess an antenna....do not possess an antennaDo they possess, claws?....Absence of claws?Do they have toxins( presence of stingers).... absence of stingers?How to create a dichotomous key?A dichotomous key is a tool used to identify species of plants, animals, or other objects based on a series of choices between pairs of contrasting characters.
To create a dichotomous key, follow these steps:
Familiarize yourself with the objects or organisms you wish to identify. Study their features and differences in detail.Choose the most important distinguishing characters of the objects or organisms and write down each pair of contrasting characters.Create the first split by choosing the most important contrasting character and writing it down as the first choice in the key.For each choice in the key, write down the possible outcomes and the next pair of contrasting characters.Continue making choices and creating new pairs of contrasting characters until you have identified all the objects or organisms.Learn more on dichotomous key here: https://brainly.com/question/24807939
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There is a block on your desk that acts as a paperweight. Its measurements are 3 cm by 4 cm by 6 cm. The block has a mass of 184.32 g. What is the block made of? 
The block on your desk given that it measures 3 cm by 4 cm by 6 cm and has a mass of 184.32 grams is made of marble
How do I know what the block is made of?To know what the block is made of, we shall determine the density of the block. Details below:
Dimensions = 3 cm by 4 cm by 6 cmVolume of block = 3 cm × 4 cm × 6 cm = 72 cm³Mass of block = 184.32 gramsDensity of block =?Density = mass / volume
Density of block = 184.32 grams / 72 cm³
Density of block = 2.56 g/mL cm³
Thus, from the calculation made above and also considering the table of densities given, we can conclude that the block is made of marble.
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Missing part of question:
See attached photo
identify each unit as belonging to si units or us customary units
The correct identification of the units is given below:
S.I Units: meter, kilogram and KelvinUS customary units: gallon. mile, pound, degrees FahrenheitWhat is the SI Unit?The SI units and the physical quantities they represent are the meter for length, the second for time, the kilogram for mass, the kelvin for temperature, the candela for light intensity, the ampere for current flow, and the mole for substance amount.
US customary units refer to the system of measures used in the US to measure objects. All other measures are conventional, including the gallon for volume, mile for length, pound for mass, and degree Fahrenheit for temperature.
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identify each unit as belonging to si units or us customary units. gallon. mile. meter. pound. kilogram. degrees farenheight. kelvin.
Why does ear escape from a tire when a tire valve is opened
Air escape from a tire when tire valve is opened because the pressure from the weight of the car is forcing the already pressurized air out .
Why does air escape from tire when tire valve is opened?When air is filled in tires, it get into more compact area than the outer atmosphere, therefore particles in tire are close to each other and exert pressure continuously on tire walls to get out of it. Thus, material of the tire need to be pressure resistant as much possible.
After opening the tire valve, air starts leaving with huge sound as strain outside the tire is weaker than that inside the tire. Molecules strike with the same force on larger area and pressure starts diminishing.
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Note: The question given on the portal is incomplete. Here is the complete question.
Question: Air leaves a tire when the tire valve is opened because
A. the pressure outside the tire is lower than the pressure inside the tire.
B. the pressure outside the tire is greater than the pressure inside the tire.
C. the temperature is higher outside the tire than inside the tire.
D. there are more gas particles outside the tire than inside the tire.
pls answer the question OR ELSE... a fly will land and perish in your beloved coffee
What is a limiting reactant?
Question 1 options:
the reactant that is in excess
the product that you can make the most of
The reactant that determines how much product can be made
the amount of reactants that react with each other
Answer:
The reactant that determines how much product can be made
Explanation:
The limiting reactant in a chemical reaction is the one that is consumed first and restricts the amount of product that may be produced (or limiting reagent).
5.6 mol N₂O.
Express your answer using two significant figures.
5.6 mol N₂O is equal to 5.6 mol. (Note: The chemical formula N₂O already specifies the number of moles, so including "mol" after the number is redundant.) The answer, rounded to two significant figures, is 5.6 mol.
What is 1 Mole?A mole is a unit of measurement in chemistry that represents an amount of a substance. One mole is defined as the amount of a substance that contains Avogadro's number of entities, where Avogadro's number is defined as 6.02214076 x 10²³ particles. This number is used to convert between mass, number of particles, and moles of a substance.
For example, one mole of a pure substance contains 6.022 x 10²³atoms, molecules, or ions, depending on the nature of the substance. The mole is a useful way to measure large amounts of chemical substances while avoiding the use of cumbersome numbers.
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What is the charge on any ion formed by an alkaline earth metal?
+4
+2
+1
+3
Answer: +2
Explanation::)
Which apply to any endothermic reaction
Answer:
Endothermic reactions: Heat is absorbed.
1) Photosynthesis: Plants absorb heat energy from sunlight to convert carbon dioxide and water into glucose and oxygen. 2) Cooking an egg: Heat energy is absorbed from the pan to cook the egg.
Explanation:
A mass of 99.7632 g of cold water at an initial temperature of 22.6°C are added to the hot water that was added to the calorimeter in the previous question. Given that the equilibrium temperature of this water was also 64.4°C, how much heat (in J) was absorbed by this mass of water? (5 sf) (Hint: I'm asking you to calculate qcold for this endothermic process).
1876.5J is the amount of heat released. Heat is the energy that moves through one body to another when temperatures are different.
What is heat?Heat is the energy that moves through one body to another when temperatures are different. Heat passes from the hotter to the colder body when two bodies with differing temperatures are brought together.
By transitioning through one physical state (or phase) to another, such as from a phase from solid to liquid (melting), from such a solids to a vapour (sublimation), from either a liquid to a vapour (boiling), either from from solid form to another, a substance can absorb heat without increasing in temperature (usually called a crystalline transition).
q=m×c×ΔT
q=99.7632× 0.45×(64.4°C-22.6°C )
q=99.7632× 0.45×41.8=1876.5J
Therefore, 1876.5J is the amount of heat released.
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The molar mass of H2O is
18.02 g/mol. What is the mass
of 6.80 moles H₂O?
?] g H₂O
The molar mass of H2O is 18.02 g/mol. Therefore, 122.4g is the mass of 6.80 moles H₂O. Water is a gaseous, liquid, as well as solid material.
What is water?Water is a gaseous, liquid, as well as solid material made of something like the chemical elements oxygen and hydrogen. It is one among the most abundant and necessary chemicals.
At room temp, it is a tasteless and odorless liquid with the critical capacity to dissolve several other compounds. Water's flexibility as either a solvent is critical to living creatures.
mass = moles × Molar mass
= 6.80 × 18
=122.4g
Therefore, 122.4g is the mass of 6.80 moles H₂O.
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For the Haber process, N₂ + 3H₂-2NH3, what theoretical volume of ammonia (NH3
hould be produced if we start with 5.0L of N₂ if STP?
29.9
10.0
22.4
44.8
Explanation:
The theoretical volume of ammonia that should be produced in the Haber process if we start with 5.0 L of nitrogen (N2) at standard temperature and pressure (STP) can be calculated as follows:
1 mole of N2 reacts with 3 moles of H2 to form 2 moles of NH3
Thus, the number of moles of N2 present can be calculated using the Ideal Gas Law:
PV = nRT
Where n is the number of moles of gas, R is the gas constant, T is the temperature in Kelvin, P is the pressure in atmospheres, and V is the volume in liters.
At STP (0°C and 1 atm), the volume of one mole of gas is 24.45 L.
Given 5.0 L of N2 at STP, the number of moles of N2 can be calculated as:
n = (PV)/RT = (1 atm)(5.0 L)/(0.0821 atmL/molK)(273 K) = 1.96 moles
The number of moles of NH3 produced can then be calculated as:
n = (2 moles of NH3)/(1 mole of N2) = 2 moles/1 mole = 2 moles
The volume of NH3 can be calculated as:
V = nRT/P = (2 moles)(0.0821 atmL/molK)(273 K)/(1 atm) = 44.8 L
So, the theoretical volume of ammonia (NH3) that should be produced if we start with 5.0 L of N2 at STP is 44.8 L.
If the rate of change of Cl₂ is -0.0520M/s, what is the rate of change of NO?
2NO(g) + Cl₂(g) → 2NOC1(g)
The reaction has a first order in Cl 2 and a second order in NO. The general order of reactions is 2+1 = 3.
How do you find the rate law?We must ascertain the values of the exponents n, m, and p as well as the rate constant, k, in order to derive a rate law. The values of the coefficients required to formulate the rate law are available to us if the reaction orders for a reaction are provided.
The reaction's rate law is rate, starting from the slow step
k'[NOCl2][NO] - (1).
Fast step is used to determine the concentration of NOCl 2, which is an intermediate.
[NOCl 2]=K[NO][Cl2] - (2)
Substitute (2) in (1)
rate=k'K[NO][Cl2][NO]
Hence, rate =k[NO]2[Cl]
The reaction has a first order in Cl 2 and a second order in NO. The general order of reactions is 2+1=3
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How many quarters do you need to do 10 loads of laundry?
This depends how much it costs per load of laundry.
For example:
If 1 load of laundry costs $2.50, this would mean that you need 10 quarters for one load. Multiply that by 10, and you get 100 quarters (the equivalent of $25).
Depending on how much the load costs, simply divide the price per load by .25 to get you total in quarters, then multiply it by 10 in this case.
The molar mass of KCI is 74.55 g/mol.
What is the mass of 0.359 mol KCI?
[?]g KCI
Mass of 0.359 mol of KCI is calculated to be 26.79 g. Mass of a given chemical element or chemical compound (g) divided by the amount of substance (mol) is called molar mass.
What is meant by molar mass?Molar mass of a compound can be calculated by adding standard atomic masses of the constituent atoms.
The mass of 0.359 mol of KCI can be calculated by multiplying the number of moles by its molar mass:
mass = moles * molar mass
mass = 0.359 mol * 74.55 g/mol
mass = 26.79 g
So, the mass of 0.359 mol of KCI is 26.79 g.
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Answer: 26.79
Explanation:
Sive the IUPAC name for each of the following structures: 1. 2. 3. 4. 5. 6. 7. 3. 9. 10. H&C. H3C. H₂C: H H3C H₂C HC ww H₂C. H3C Br CH3 CH3 CH3 H Br CH3 CH 3 'Br CH3 CH 3 CH 3 CH 3 CH 3 CH3 CH3 CH3
The IUPAC was founded in 1919 by academics and researchers who realized the need for chemical standardization. Therefore, in the below given ways molecules can be named.
What is IUPAC ?The International Union of Pure as well as Applied Chemistry is abbreviated as IUPAC. It belongs to an international scientific publication with no government affiliation. The IUPAC works to develop chemistry by, among other things, establishing international quality standards for nomenclature, symbols, as well as units.
The IUPAC was founded in 1919 by academics and researchers who realized the need for chemical standardization. The International Union of Pharmaceutical Societies (IACS), the IUPAC's forerunner, convened in Paris in 1911 to discuss topics that needed to also be addressed.
CH[tex]_3[/tex] methane
CH[tex]_3[/tex]CH[tex]_3[/tex] ethane
CH[tex]_3[/tex]CH[tex]_2[/tex]CH[tex]_3[/tex] propane
Therefore, in the above given ways molecules can be named.
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How much heated must be absorbed by 125 g of ethanol to change temperature from 21.5 to 34,8 C
Answer:
4.02 kJ
Explanation:
We must convert the answer to kJ 4023.25 J . 1kJ /1000 =4.02kJ
Phosphoric acid = Pyrophosphoric Acid & Water
No, that is not correct. Phosphoric acid (H3PO4) and pyrophosphoric acid (H4P2O7) are two different chemical compounds. Phosphoric acid is a tri-protic acid with three acidic hydrogens, while pyrophosphoric acid is a diphosphoric acid with two acidic hydrogens.
What happens when phosphoric acid is mixed with water?When phosphoric acid is mixed with water, it dissolves to form a solution of hydrogen ions (H+) and phosphate ions (PO4-). The concentration of hydrogen ions can be adjusted by adding more or less water to the solution, which changes the pH of the solution.
Pyrophosphoric acid is a more complex molecule than phosphoric acid, and its behavior in water is different.
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What is the best description of blood.
(a)sol (b) solution (c)foam (d) liquid aerosol
Answer:
Explanation:
liquid
HELP PLS
how do I prove a chemical formula of a compound using the Lewis structure ??
1. Determine the total number of valence electrons in the molecule or ion.
• Add together the valence electrons from each atom. (Recall that the number of valence electrons is indicated by the position of the element in the periodic table.)
•If the species is a polyatomic ion, remember to add or subtract the number of electrons necessary to give the total charge on the ion.
2. Arrange the atoms to show specific connections.
• When there is a central atom, it is usually the least electronegative element in the compound.
• Chemists usually list this central atom first in the chemical formula, which is another clue to the compound’s structure.
• Hydrogen and the halogens are almost always connected to only one other atom, so they are usually terminal rather than central.
3. Place a bonding pair of electrons between each pair of adjacent atoms to give a single bond.
• In H2O, for example, there is a bonding pair of electrons between oxygen and each hydrogen.
4. Beginning with the terminal atoms, add enough electrons to each atom to give each atom an octet (two for hydrogen).
• These electrons will usually be lone pairs.
5. If any electrons are left over, place them on the central atom.
• Some atoms are able to accommodate more than eight electrons.
6. If the central atom has fewer electrons than an octet, use lone pairs from terminal atoms to form multiple (double or triple) bonds to the central atom to achieve an octet.
• This will not change the number of electrons on the terminal atoms.
7. Final check
• Always make sure all valence electrons are accounted for and each atom has an octet of electrons except for hydrogen (with two electrons).
To prove the chemical formula of a compound using the Lewis structure, you need to follow these steps:
1. Draw the Lewis structure of the compound: Start by drawing the Lewis structure of the compound using the valence electrons of each atom. The valence electrons are the outermost electrons of an atom, which participate in chemical bonding. To determine the valence electrons of an atom, you can refer to its position in the periodic table.
2. Determine the number of electrons in the compound: Count the total number of valence electrons in the compound by adding up the valence electrons of each atom in the compound. This number is equal to the sum of the valence electrons of all the atoms in the compound.
3. Determine the number of electron pairs in the compound: Count the number of electron pairs in the compound by dividing the total number of valence electrons by 2. This gives you the number of electron pairs in the compound.
4. Determine the connectivity of the atoms: Identify the connectivity of the atoms in the compound by drawing the lines that connect the atoms in the Lewis structure. Each line represents a bond between the atoms.
5. Determine the formal charge of each atom: Calculate the formal charge of each atom in the compound by subtracting the number of lone pair electrons and half the number of bonding electrons from the total number of valence electrons for that atom. The formal charge of an atom should be as close to zero as possible.
6. Write the chemical formula: Write the chemical formula of the compound by using the symbol of each atom in the compound, along with its subscript, which corresponds to the number of atoms of each element present in the compound.
By following these steps, you can use the Lewis structure of a compound to prove its chemical formula.
If you put 1.50 moles of N2 and 4.00 moles of O2 gas in a 45.0 L container at a temperature of 45°C, what is the total pressure of the system?
30 points
If you put 1.50 moles of N2 and 4.00 moles of O2 gas in a 45.0 L container at a temperature of 45°C, the total pressure of the system is 323.1 atm.
What ideal gas law ?The ideal gas law, also known as the general gas equation, is the state equation for a hypothetical ideal gas. Although it has several limitations, it is a good approximation of the behavior of many gases under many conditions.
Given;
N = 5.50 moles
V = 45.0 L
R = gas constant 8.314
T = 318 kelvin
P = ?
By an Ideal gas equation,
PV = nRT
By substituting this values in ideal gas equation, and we get as follows:
P = nRT / V
= 5.50 × 8.314 × 318 / 45.0
= 323.1 atm
Thus, the total pressure of the system is 323.1 atm.
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What type of decay is this?
An illustration of beta decay is the decay of technetium-99, which has too many neutrons to be stable. A proton and a beta particle are created from a neutron in the nucleus.
Along with the beta particle, the nucleus also releases some gamma radiation. The new atom has 44 protons rather than the same number of mass protons.
What does beta decay's symbol mean?β A high-speed electron known as a beta particle () is released from an atom's nucleus during various types of radioactive decay. In an equation, the symbol for a beta particle is either or e01. The beta decay of carbon-14 transforms it into a nitrogen-14 nucleus.
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What was Flint’s response to the Virginia Tech research findings?
State of emergency was proclaimed in Flint, the county seat of Genesee, by Michigan Governor Rick Snyder on January 5, 2016. Shortly after, President Barack Obama announced a federal state of emergency, approving further assistance from the Department of Homeland Security and the Federal Emergency Management Agency.
What is the Flint water crisis?A public health emergency known as the Flint water crisis began in 2014 when the drinking water in Flint, Michigan was found to be tainted with lead and possibly Legionella bacteria. Flint switched its water source from treated Detroit Water and Sewerage Department water (obtained from Lake Huron and the Detroit River) to the Flint River in April 2014 due to a budget issue.
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A flask with a volume of 250.0
mL contains air with a density of 1.126
g/L. What is the mass of the air contained in the flask?
A flask with a volume of 250.0 mL contains air with a density of 1.126 g/L. The mass of the air contained in the flask is 0.28 gram.
What do you mean by density ?The density of a material is the measure of how tightly it is packed together. It is expressed as mass per unit volume. Density Symbol is D or
Formula Density = m/V, where is the density, m is the object's mass, and V is the object's volume.
Given:
Volume = 250.0 mL
Convert 250.0 mL in Liters :
250. 0 / 1000 = 0,25 L
Density = 1.126 g/L
Mass = g ?
Mass = Density × Volume
Mass = 0.25 × 1.126
Mass = 0.28 gram
Thus, the mass of the air contained in the flask is 0.28 gram.
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_Na₂SO4 (aq) + _____ BaCl₂ (aq) → ______ BaSO4(s) +
Which coefficients balance the equation?
OA. 1,1,1,2
OB. 1,2,1,2
OC. 2,1,1,2
OD. 2,1,2,1
NaCl (aq)
Answer:
A
Explanation:
Na2SO4 +BaCl2 ____BaSO4+2NaCl
For the reaction
C+ O2 → CO2,
what is the maximum amount of CO2 which
could be formed from 3.67 mol of C and
4.23 mol of O₂?
Answer in units of g.
179.43 g/mol is the maximum amount of CO₂ which could be formed from 3.67 mol of C and 4.23 mol of O₂.
What is chemical reaction?
When molecules in a reactant undergo a chemical reaction, their bonds are broken, and molecules in the product undergo a similar process, new bonds are created, creating a new substance.
We are surrounded by chemical reactions on a daily basis, whether it be in our bodies as they process food or in the sun as they produce the light we see. Prior to starting with chemical reactions, it's crucial to understand physical and chemical changes.
C + O₂ → CO₂
carbon = 12.01g/mol
12.01 × 3.67
= 44.07 g/mol
O₂ = 32/mol
= 32 × 4.23
= 135.36 g/mol
44.07 g/mol + 135.36 g/mol
= 179.43 g/mol
Thus, 179.43 g/mol is the maximum amount of CO₂ which could be formed from 3.67 mol of C and 4.23 mol of O₂.
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Use your knowledge about chemical reactions; explain why gold coins and silver coins found at the bottom of the sea withstand the elements of the sea differently? Hint: gold coins mostly retain their gold finish.
According to the electronic configuration , gold and silver are inert metals and hence withstand the elements of the sea differently.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule.
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When 2 moles of ammonia (NH₃) decomposes into nitrogen gas (N₂) and hydrogen gas (H₂), how many moles of nitrogen gas are produced?
The decomposition of 2 moles of ammonia gas will give one mole of nitrogen gas and 3 moles of hydrogen gas. This is an endothermic reaction.
What is ammonia ?Ammonia is an inorganic gas formed by the combination of nitrogen gas and hydrogen gas. The industrial synthesis of ammonia gas is known as Haber process.
The formation of ammonia is a reversible process and ammonia can decompose to form the constituent gases nitrogen and hydrogen.
The balanced chemical equation of the decomposition of ammonia gas is written as follows:
[tex]\rm 2NH_{3} \rightarrow 3H_{2} + N_{2}[/tex]
Therefore, the decomposition of 2 moles of ammonia gas will produce one mole of nitrogen gas.
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A total of 2.00 mol of a compound is allowed to react with water in a foam coffee cup and the reaction produces 191 g of solution. The reaction caused the temperature of the solution to rise from 21.00 to 24.70 ∘C . What is the enthalpy of this reaction? Assume that no heat is lost to the surroundings or to the coffee cup itself and that the specific heat of the solution is the same as that of pure water. Enter your answer in kilojoules per mole of compound to three significant figures.
The enthalpy of this reaction is 1.48 kJ/mol.
The formula to calculate heat energy is
Q = m × c × ΔT
ΔT = T₂ - T₁
m = mass (grams)ΔT = T₂ - T₁ = 24.70 - 21.00 = 3.70 °C
Q = m × c × ΔT
Q = 191 × 4.184 × 3.70
Q = 2,956.83 J
Q = (2,956.83 ÷ 1,000) kJ
Q = 2.96 kJ
The enthalpy ΔH = Q ÷ n
n = number of moles = 2.00 molQ = heat energy = 2.96 kJΔH = enthalpyΔH = Q ÷ n
ΔH = 2.96 ÷ 2.00
ΔH = 1.48 kJ/mol
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food safety guidelines recommended that a beef rib roast bone in should cook for 23.0 minutes per pound based on 325°F oven setting. how many hours should it take to cook a 5.17 pound roast?
Food safety guidelines recommended that a beef rib roast bone in should cook for 23.0 minutes per pound based on 325°F oven setting. 2 hours should it take to cook a 5.17 pound roast.
What is food safety ?Food safety is concerned with how food is handled, stored, and prepared in order to prevent infection and ensure that our food contains enough nutrients for us to maintain a healthy diet.
It takes 23 min per one lb (pound)
Then it takes how many min for 5.17 pound
= 23 min / pound x 5.17pound
= 118.91 min x 1hr / 60 min
= 1.982hr
≅ 2 hrs
Thus, 2 hours should it take to cook a 5.17 pound roast.
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8.4×10−2 g Sr Express your answer using two significant figures.
Taking into account the definition of significant figures, 8.4×10⁻² g expressed using two significant figures is 8.4×10⁻² g
Definition of significant figuresSignificant figures are the digits of a number that are considered nonzero and have a real meaning and, therefore, provide some information.
To establish the significant figures you must bear in mind that:
Any number other than zero is considered significant.Zeros located between two digits other than zero and those located after the decimal point are considered significant figures.The leading zeros of the first non-zero digit are useful for fixing the position of the decimal point and are not significant.Significant figures in this caseScientific notation is useful because it makes it easier to understand the value of measurements, especially when they have very large or very small values, and it helps to identify significant figures.
To express a measurement in scientific notation, the first significant figure is placed starting from the left in the units position, followed by the decimal point and the rest of the significant figures. The number obtained is then multiplied by the power of 10 needed to retrieve the original number.
Then, in this case, 8.4×10⁻² g expressed using two significant figures is 8.4×10⁻² g, since 8 and 4 are the two significant digits.
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