Based on what basis the elements had been arranged
in the modern periodic table?
A - The increase in the atomic mass
B – The increase in the atomic number
C - The classification of elements into metals and
nonmetals
D - The classification of elements according to their
Answer:
B
The increase in the atomic number
How do we get energy from the food we eat?
A
The constantly moving molecules in food give us kinetic energy.
B
Breaking the molecular bonds in the food releases stored chemical energy.
C
Eating hot food transfers thermal energy to our bodies.
D
The chemical energy stored in the food is transferred to us as thermal energy.
BACK
Answer:
A
Explanation:
I used my resources and they was explaining and I came to a resolution that it was A
What is the mass in grams of 2.70 moles of zinc (II) oxide?
Answer:
219.73 g
Explanation:
The molecular formula of zinc (II) oxide is ZnO. This means its molar mass would be:
Molar Mass of ZnO = (Atomic Mass of O) + (Atomic Mass of Zn)Molar Mass of ZnO = 16 + 65.38 = 81.38 g/molWith that molar mass, we can convert moles into grams:
mass = moles * molar massmass = 2.70 moles * 81.38 g/mol = 219.73 gWhich of the following gases was NOT part of Earth’s original atmosphere?
Answer:anser choices
Explanation:
Answer:oxygen hahah
Explanation:
Find the mass of 3.66 moles of Octane C,H,8
Answer:
417.2g
Explanation:
Given parameters:
Number of moles of octane = 3.66moles
Unknown:
Mass of octane = ?
Solution:
To solve this problem;
Octane = C₈ H₁₈
Mass of octane = number of moles x molar mass
Molar mass of octane = 8(12) + 18(1) = 114g/mol
Mass of octane = 3.66 x 114 = 417.2g
Balance the following Equation Show your work.
1.____CaO + ____H2O → ____Ca(OH)2
2. ___HgO → ___Hg + ____O2
3. ___KI + ___Pb(NO3)2 → ____PbI2 + ___KNO3
4. ___Al + ___Cl2 → ___AlCl3
5. ___KBr + ___Cl2 → ___KCl + ____Br2
6. __Mg3(PO4)2 + __NaOH → __Na3PO4 + __Mg(OH)2
7. ___H2O → ___H2 + ___O2
8. ___CH4 + __O2 → __CO2 + __H2O
9. ___C2H6 + ___O2 → ___CO2 + ___H2O
10. ___H2 + ___N2 → ___NH3
Answer:
1) alr balanced
2) 2 2 1
3) 2 1 1 2
4) 2 3 2
5) 2 1 2 1
6) 1 6 2 3
7) 2 2 1
8) 1 2 1 2
9) 2 5 4 6
10) 3 1 2
Please help me if your good with science:).
What is the speed of the train?
A.)1200km/h
B.)4 km/h
C.)75 km/h
D.)300 km/h
explain why aluminium oxide must be molten for electrolysis to take place.
Answer:
The extraction is done by electolysis but first the aluminium oxide must be melted so that electricity can pass through it...The use of molten cryolite as a solvent reduces some of the Energy
costs involved in extracting aluminum by allowing the ions in aluminum oxide to move freely at low temperature ..
PLEASE HELPPPPP 12 POINTS
Answer: It most likely represents a canyon.
OK BE HONEST..... anyone here like hawain pizza owo?
A gas container was filled with 2.3 moles of nitrogen gas. If the original volume
was 3.4 what would be the new volume if the container ended with 5.7 moles of
nitrogen?
Answer:
V₂ = 8.43 L
Explanation:
Given data:
Initial number of moles = 2.3 mol
Initial volume = 3.4 L
Final volume = ?
Final number of moles = 5.7 mol
Solution:
According to Avogadro law,
The number of moles of gas is directly proportional to its volume. By increasing the number of moles volume also goes to increase.
Mathematical relationship:
V₁ / n₁ = V₂ / n₂
By putting values,
3.4 L / 2.3 mol = V₂ / 5.7 mol
V₂ = 3.4 L× 5.7 mol / 2.3 mol
V₂ = 19.38 L.mol / 2.3 mol
V₂ = 8.43 L
What process formed the water droplets in Scott's model? O evaporation O transpiration o condensation O precipitation
Answer: My guess would be condensation.
Explanation: Condensation makes water into water droplets.
What is the potential energy of a bird sitting in a tree if the bird has a mass of 2Kg and it is 10 meters above the ground?
The potential energy of a bird : 196 J
Further explanationGiven
mass of bird = m = 2 kg
height = h = 10 m
Required
The potential energy
Solution
Potential energy is the energy that objects have because of their position. Usually related to the earth's gravitational force
Can be formulated
PE = m g h
g = acceleration due to gravity ⇒ 9.8 m/s²
Input the value :
PE = 2 kg x 9.8 m/s² x 10 m
PE = 196 J
PLS HELP!!!!! 30 POINTS!!!!
Groups of students weighed three different samples of magnesium sulfate. The samples actually weigh 5.25 grams each. Determine whether each group’s data set is accurate, precise, both, or neither.
Drag the tiles to the correct boxes to complete the pairs.
Answer:
1. accurate but not precise
2. precise but not accurate
3. accurate and precise
4. neither
Explanation:
hope this helps :)
The accuracy is always followed by precision, but a high degree of precision does not imply accuracy. All the accurate results will be definitely precise.
What is accuracy and precision?The accuracy of a determination is defined as the concordance between the result and the true value or most probable value. The precision of a determination is known as the concordance of a series of measurements of the same quantity.
The accuracy expresses the correctness of a measurement while precision of a set of results expresses the reproducibility of a measurement.
Accuracy is related to how close the observed result is to the true value while precision is related to how close the measurements are to each other.
The given measurements are denoted as:
1. Accurate but not precise
2. Precise but not accurate
3. Accurate and precise
4. Neither
Thus accurate results will be precise but precise results may not be accurate.
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What is the resistance of a blub when the voltage across is 6 V and the current is 0.2A?
Answer:
30 Ohms (Ω)
Explanation:
Resistance = Voltage/Current
R = 6/0.2
R = 30 Ohms (Ω)
When determining reaction orders by experiment, the most common procedure is to ______. Multiple choice question. keep all reactant concentrations constant for each determination change all reaction concentrations by the same amount each time change the concentration of one reactant while keeping the other concentrations constant
Answer:
change the concentration of one reactant while keeping the other concentrations constant
Explanation:
For a given reaction;
A + B --> C + D
The reaction rate may be given as;
Rate = k[A][B]
In the above rate equation, the orders of both reactants ( A and B) is 1 . Reaction order is basically how the concentration of the reactant affect the rate of the equation.
The correct option is;
change the concentration of one reactant while keeping the other concentrations constant.
That way, one can monitor how a particular reactant affect the rate of the reaction.
What colour is Calcium Hydroxide solution
Answer:
Lime
Explanation:
50 POINTS!!!
Read the sentence from the section “The Law Of Conservation Of Mass."
In a physical change, a substance's physical properties may change, but its chemical makeup does not.
Which of the following words, if it replaced the word "properties" in the sentence above, would CHANGE the meaning of the sentence?
a. possessions
b. attributes
c. characteristics
d. qualities
Answer:
A
Explanation:
Write a word equation for the combustion of propane???
HELP????
Answer:
1 mole of propane combines with 5 moles of oxygen gas to produce 3 mole of carbon dioxide and 4 moles of water.
Explanation:
The word equation for the combustion of propane can be obtained from the chemical equation;
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
The word equation is therefore:
1 mole of propane combines with 5 moles of oxygen gas to produce 3 mole of carbon dioxide and 4 moles of water.
For such a combustion reaction, carbon dioxide and water are produced in the process.
What is the mass number of an atom that contains 12 protons, 14 neutrons, and 12 electrons? *
10 points
2
26
24
168
The mass number of an atom : 26
Further explanationGiven
12 protons, 14 neutrons, and 12 electrons
Required
The mass number
Solution
Inside the atom there are 3 sub-particles, namely protons, neutrons and electrons. Protons and electrons are present in the atomic nucleus while electrons move around the atomic nucleus through energy levels in the atomic shell
Atomic number = number of protons = number of electrons
Mass number = number of protons + number of neutrons
Input the value :
Mass number = 12 + 14
Mass number = 26
What happens to the energy that is stored in cells? Check all that apply.
It is released slowly.
It is released quickly.
It is released in a single reaction.
It is released in a series of reactions.
It is used by cells for repair and growth.
Calculate the number of carbon atoms contained in 5.6 g of C2H4
Molecular mass of C₂H₄ is,
M = 2×12 + 4×1 g/mol
M = 28 g/mol
Moles of C₂H₄ in 5.6 g of C₂H₄ :
n = 5.6/28 mol
n = 0.2 mol
Now, 1 mol of C₂H₄ contains 2 moles of carbon.
So, number of moles of carbon are :
n = 0.4 mol
We know, 1 mol of any atom contains 6.022 × 10²³ atoms.
So, number of carbon atoms are :
[tex]N = 0.4 \times 6.022\times 10^{23} \\\\N = 2.409 \times 10^{23}[/tex]
Hence, this is the required solution.
because of friction?
Answer:
what do you mean?
Explanation:
Name the main chemical in baking powder
Answer:
sodium bicarbonate
Answer:
Baking powder
Explanation:
Baking powder is a solid mixture that is used as a chemical leavening agent in baked goods. It can be composed of a number of materials, but usually contains baking soda (sodium bicarbonate, NaHCO3), cream of tartar (potassium bitartrate, C4H5KO6), and cornstarch. (A base, an acid, and a filler respectively.)
If a car was driving 45 miles per hour northeast, and is now driving 30 miles per hour
north,
A
the car's velocity decelerated.
B
the car's velocity accelerated.
с
the car's velocity remained unchanged.
D
the car's acceleration is 30 miles per hour.
Answer:
A
Explanation:
What do the dots in this image represent?
Ionic bonds in water
Covalent bonds in water
Shared valence electrons
Unshared/lone pairs of valence electrons
The dot in the image represents the unshared/ lone pair of electrons. The correct option is D. Dots are written around the element in an equation.
What are unshared electrons?Unshared or lone electrons are those electrons, which are lone and not shared with another atom when making a covalent bond. These electrons are represented by dots. The valence electron help in making the valence complete of other atoms when forming a bond.
The diagram is of water, oxygen has six valence electrons, of which two are shared by hydrogen and four are lone electrons. The lone pairs will be attached to other hydrogen molecules.
Thus, the correct option is D, Unshared/lone pairs of valence electrons regarding the representation of the dots in the image given.
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HELP PLEASE!
How many molecules are in 6.06 grams of NH3?
(please show steps so I can understand what I'm supposed to do to get the answer)
How many moles are equal to 89.23g of aluminum chloride, AlCl3?
Answer:
[tex]\boxed {\boxed {\sf 0.6692 \ mol \ AlCl_3}}[/tex]
Explanation:
To convert from grams to moles, we must use the molar mass. This can be calculated using the Periodic Table.
1. Molar Mass
First, identify the elements in the compound AlCl₃. They are aluminum and chlorine. Now find the masses:
Al: 26.981538 g/mol Cl: 35.45 g/molTake a look at the compound. There is a subscript of 3 after chlorine, so we must multiply its molar mass by 3 then add aluminum's.
AlCl₃= 3(35.34 g/mol) + 26.981538 g/mol = 133.331538 g/mol2. Convert Grams to Moles
We can use the molar mass as a ratio.
[tex]\frac{133.331538 \ g \ AlCl_3}{1 \ mol \ AlCl_3}[/tex]
Multiply by the given number of grams: 89.23
[tex]89.23 \ g \ AlCl_3 * \frac{133.331538 \ g \ AlCl_3}{1 \ mol \ AlCl_3}[/tex]
Flip the fraction so the grams of aluminum chloride cancel out.
[tex]89.23 \ g \ AlCl_3 * \frac{1 \ mol \ AlCl_3}{133.331538 \ g \ AlCl_3} = 89.23 \ * \frac{1 \ mol \ AlCl_3}{133.331538}[/tex]
[tex]\frac{89.23 \ mol \ AlCl_3}{133.331538}[/tex]
[tex]0.6692340112 \ mol \ AlCl_3[/tex]
3. Round
The original measurement of grams has 4 significant figures. We must round to 4 sig figs.
For the number we calculated, that is the ten thousandth place.
The 3 in the hundred thousandth place tells us to leave the 2.
[tex]0.6692 \ mol \ AlCl_3[/tex]
There are about 0.6692 moles of aluminum chloride in 89.23 grams.
What is energy
O The ability to do work.
O renewable particles
O stored particles
moving particles
Explain which has a greater impact on the kinetic energy of an object - the
object's mass or the object's speed?
Answer:
it is the objects mass, I learned this last semester
The object's mass has a greater impact on the kinetic energy of an object as it is the mass the mass on which force is exerted and in which energy is stored to be transformed in to kinetic energy.
What is force?Force is defined as a cause which is capable of changing the motion of an object. It can cause an object which has mass to change it's velocity. It is also simply a push or a pull . It has both magnitude as well as direction.Hence, it is a vector quantity.
It has SI units of Newton and is represented by'F'.Newton's second law states that force which acts on an object is equal to momentum which changes with time. If mass of object is constant, acceleration is directly proportional to net force acting on an object.
The concepts which related to force are thrust and torque .Thrust increases the velocity of an object and torque produces change in rotational speed of an object.
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