Can someone please help me with these questions
Answer:
1. 40 grams
2. 20 grams
Explanation:
every 10 years, divide by 2
year 0; 80
year 10; 40
year 0; 80
year 10; 40
year 20; 20
please give thanks by clicking heart button! :)
(2k-1)²
what the answer pls.
Answer:
4k^2-4k+1
Explanation:
Plx give brainlyest
There is a photon with a frequency of 8x10^12 Hz. What is the energy of this
photon?
Answer:
33.085476 meV ≈ 33 meV
Explanation:
Hope this helped!
How would you compare young soil to soil that has been around a long time?
Answer:
young soil has less organic materiel that old
Explanation:
A current of 1.5A was passed through two electrolytes arranged
in series for 10 minutes and 2.16 g of silver deposited on the cathode
of the first cell. (Atomic wt. of Ag=108 ,Ni =59) .Calculate
a) The quantity of electricity that passes through the two cells.
b) The amount of Nickel deposited on the cathode of the second cell
containing Nickel(II) nitrate, Ni(NO3)2 ?
Answer:
0.59 g
Explanation:
The reaction at the first cathode;
Ag^+(aq) + e -----> Ag
if Q = It = 1.5 * 10 * 60 = 900C
According to Faraday's second law of electolysis; if we pass the same quantity of electricity through different electrolytes, the mass of substances deposited on each cathode is proportional to the equivalent weights.
Equivalent weight E = Atomic mass/valency
For Ag = 108/1 = 108
For Ni = 59/2 = 29.5
Hence
Let m1 = mass of Ag deposited =2.16
Let m2 = mass of Ni deposited
Let E1 = equivalent weight of Ag
Let E2 = equivalent weight of Ni
m1/m2 = E1/E2
2.16/m2 = 108/29.5
m2 = 2.16 * 29.5/108
m2 = 0.59 g
How many valence electrons do the elements in column 4 have? Are these elements very reactive?
Answer:
Explanation: Elements in group 14 have 4 valence electrons. Meaning that to achieve a stable octet they need to either gain or lose 4 electrons in total. That would take significantly more energy than other elements, e.g., group 1 (alkaline metals) or group 17 (halogens.)
Explanation:
In the periodic table, the elements in column 4 have four valence electrons and are less reactive compared to s- block elements but more reactive than the p-block elements.
What is periodic table?Periodic table is a tabular arrangement of elements in the form of a table. In the periodic table, elements are arranged according to the modern periodic law which states that the properties of elements are a periodic function of their atomic numbers.
It is called as periodic because properties repeat after regular intervals of atomic numbers . It is a tabular arrangement consisting of seven horizontal rows called periods and eighteen vertical columns called groups.
Elements present in the same group have same number of valence electrons and hence have similar properties while elements present in the same period show gradual variation in properties due to addition of one electron for each successive element in a period.
Learn more about periodic table,here:
https://brainly.com/question/11155928
#SPJ2
9. If one bulb of Christmas lights, connected in series is burned out, what will
happen to the other light bulbs?
A. All other bulbs will no longer work.
B. All other bulbs will continue to light
C. The brightness of the bulbs will increase.
D. The brightness of the bulbs will decrease.
10. Three light bulbs with resistances 2000 , 1600 , and 800 are connected in
series respectively. Which one has the highest brightness when the circuit is
plugged to a 220 V voltage source?
A. 800 2
B. 1600 2
C. 2000 2
D. none of the above
Answer:
A. all other bulbs will no longer work
What is the base name for the following compound?
C-C-C-C-C=0
Answer:
Ethanoic Acid
Explanation:
A bicycle weighs 780. pounds. If the pressure exerted by its
tires on the ground is 30.5 pounds per square centimeter, what
is the area of one of the two tires that's in contact with the
road? (This will be half as much as the pressure exerted by
both tires.)
Answer:it’s 12.8cm^2 and I saw that last anwser and he’s not wrong but yeah I had trouble figuring it out but it’s just force divided by area for both tires multiply that by 2
Explanation:
A bicycle weighs 780. pounds. If the pressure exerted by its tires on the ground is 30.5 pounds per square centimeter, the area of one of the two tires that's in contact with the road is 12.8cm².it’s just force divided by area for both tires multiply that by 2.
What is pressure ?Pressure is defined as the force applied perpendicular to an object's surface per unit area over which that force is distributed. Gauge pressure is the pressure in relation to the surrounding atmosphere. Pressure is expressed using a variety of units.
Pressure is defined as force per unit area of surface; the SI unit of pressure is the pascal (Pa), which is defined as one newton per square metre (N/m2). An object's pressure is proportional to the force it exerts and inversely proportional to the area over which the force is exerted.
The physical force exerted on an object is defined as pressure. The force applied per unit area is perpendicular to the surface of the objects. F/A is the basic pressure formula (Force per unit area).
Thus, the area of one of the two tires that's in contact with the road is 12.8cm².
To learn more about the pressure, follow the link;
https://brainly.com/question/29341536
#SPJ2
Please answer this...
HELP
1) A 400g sample of alcohol (c = 2.43 J/g°C) at 16°C is mixed with 400g
of water (c = 4.19 J/g°C) at 85°C. What is the final temperature of the
mixture?
Answer:
Explanation:
Given data:
Mass of alcohol = 400 g
Specific heat capacity of alcohol = 2.43 J/g°C
Initial temperature of alcohol = 16°C
Mass of water = 400 g
Specific heat capacity of water = 4.19 J/g°C
Initial temperature of water = 85°C
Final temperature of mixture = ?
Solution:
Equation:
m₁c₁ (T₂-T₁ ) = m₂c₂(T₂-T₁)
by putting values,
400 × 4.19 × (T₂ - 85°C) = 400 × 2.43 × (T₂ - 16°C)
1676 × (T₂ - 85°C) = 972 × (T₂ - 16°C)
why is ketchup a physical change
Answer:
Ketchup is not a change, it is a sauce.
Explanation:
Answer:
There is no change in the tomatos structure its "state of matter" you could say is changed, but the actual chemical compoud is the same.
what does the pH scale for acids and bases range from?
Answer:
Anything below 7.0 is acidic, and anything above 7.0 is alkaline, or basic. pH scale, ranging from 0 (very acidic) to 14 (very basic/alkaline) and listing the pH values of common substances.
Explanation:
PRESS THE CROWN
The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic.
Explanation:
How do the products of chemical reactions compare to their reactants? Question 7 options: The products usually weigh more than the reactants. The products often have completely different properties than the reactants. The products usually have more atoms than the reactants. The products are usually more toxic than the reactants
Answer:
The second choice.
Explanation:
The products often have completely different properties than the reactants.
The first and third are wrong because matter is always preserved in a chemical reaction.
The last is not true.
Which substance is the limiting reactant when 12 g of sulfur reacts with 18 g of oxygen and 24 g of sodium hydroxide according to the following chemical equation?
NaOH is the limiting reactant
Further explanationGiven
12 g of sulfur reacts with 18 g of oxygen and 24 g of sodium hydroxide
Required
The limiting reactant
Solution
Reaction
2 S(s) + 3 O₂(g) + 4 NaOH(aq) ⇒ 2 Na₂SO₄(aq) + 2 H₂O(l)
mol S(MW=32.065 g/mol) :[tex]\tt \dfrac{12}{32.065}=0.374[/tex]
mol O₂(MW=32 g/mol)[tex]\tt \dfrac{18}{32}=0.5625[/tex]
mol NaOH(MW=40 g/mol)[tex]\tt \dfrac{24}{40}=0.6[/tex]
A method that can be used to find limiting reactants is to divide the number of moles of known substances by their respective coefficients, and the smallest ratio becomes a limiting reactant
S : O₂ : NaOH =
[tex]\tt \dfrac{0.374}{2}\div \dfrac{0.5625}{3}\div \dfrac{0.6}{4}=0.187\div 0.1875\div 0.15\Rightarrow NaOH~smallest~ratio[/tex]
Please help me with this question
Answer:
Moon
Explanation:
calculate the mass in gram of binormal solution in NAOH
Answer:
80 grams
Explanation:
Normality is one of the units of concentration and it is derived by dividing the gram or mole equivalent of the solute in a solution by the volume (in liters) of the solution.
The equivalent weight of NaOH is derived by dividing the molecular weight of the compound by 1. Hence, the equivalent weight of NaOH in 1 normal solution is 40/1 = 40 g.
If 1 normal NaOH solution contains 40 g of NaOH in 1 liter of the solution, then a binormal (2 normal) solution of NaOH would contain;
2 x 40 = 80 g of NaOH.
What is the differences in the densities of the Continental crust and the oceanic crust and why are they different?
Answer:
Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. ... Because continental crust is less dense than oceanic crust it floats higher on the mantle, just like a piece of Styrofoam floats higher on the water than a piece of wood does
Adenosine triphosphate is the:
A. mitochondria
B. energy molecule
C. chloroplast
D. cellular respiration
Answer:
B. Energy Molecule
Explanation:
Adenosine triphosphate, or ATP, is the primary carrier of energy in cells. The water-mediated reaction known as hydrolysis releases energy from the chemical bonds in ATP to fuel cellular processes. Adenosine triphosphate (ATP), energy-carrying molecule found in the cells of all living things.
Answer:
B. Energy Molecule
Explanation:
It is used for storing and transferring energy in cells.
Clear selection
2. What is the main function of white blood cells?
10 points
O a. to carry oxgen rich blood
O b. to carry carbon dioxide
O c. to help fight disease
O d. to help build your red blood cells
Answer:
C
Explanation:
To hello fight disease
The ionization energies for successive removal of electrons from sodium are as follows: 496kJ, 4562kJ, 6912kJ, and 9544kJ. What does the jump in ionization energy indicate
Answer:
It is difficult to remove electrons from cations because one or more electrons are already lost and hold of nucleus on remaining electrons increase
Explanation:
which of the following substance is most likely basic
Answer:
Please provide answer options. :)
if a aluminum rod was made out of solid glass instead of solid aluminum what would happen.
Answer:
it would break when it hits the ground
Explanation:
Which of the following statements is correct?
Group of answer choices
Water and nitrogen are both compounds.
Water and nitrogen are both elements.
Water is an element and nitrogen is a compound.
Water is a compound and nitrogen is an element.
Answer:
water is a compound and nitrogen is an element
Explanation:
water is a compound and also a molecule because it is a combination of two different element, while nitrogen is an atom or an element
Answer: Water is a compound and nitrogen is an element.
Explanation:
Water = H20 = 2 Hydrogen atoms and 1 Oxygen atom
Nitrogen (N) element of Group 15 of the periodic table
How many joules are needed to change the temperature of 25 g of water from 40 C to 100 C?
Answer:
Explanation:
2
will give brainlist!!!
21. Which answer best describes the coast?
A. thick deposits of sediments carried off of the shelf
B. the surf area along coastlines
C. 75 mile shallow flat area just off coastlines
D. area of land that drops toward deep ocean basins
Answer:
C
Explanation:
75 mile shallow flat area just off coastlines
How many kilograms of iron can be obtained from 100 kilograms of Fe203
Answer:
754
Explanation:
What is the empirical formula for propene (C3H6)?
C2H4
O C4H8
O C3H6
O CH2
Answer:
D) CH2
Explanation:
The empirical formula of propene is CH₂ as it has chemical formula of C₃H₆ which on division of subscripts give empirical formula as CH₂.
What is empirical formula?Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.
Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.
Learn more about empirical formula,here:
https://brainly.com/question/11588623
#SPJ6
how many grams of hydrogen are required to react completely with 400g nitrogen to form ammonia? Pls help
N2+3H2-->2NH3
first we find the number of nitrogen moles
the molar mass for N2 is 14+14=28g/mole
to find the number of moles we divide the mass by the molar mass
n=400/28=14.28 moles
for 1 mole of N2 we use 3 moles of H2, therefore for 14.28 moles of N2 we use 14.28*3=42.84 moles ofH2
to find the mass of H2 we multiply the number of moles by the molar mass
the molar mass of H2 is 2g/mole
2*42.84=85.68g of H2
What is specific heat a measure of?
O A. How much energy it takes to break chemical bonds
B. How much energy it takes to heat a substance
C. How much energy it takes to vaporize a substance
D. How much energy it takes to melt a substance
Answer:
B. How much energy it takes to heat a substance
Explanation:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
The substances with higher value of specific heat capacity require more heat to raise the temperature by one degree as compared the substances having low value of specific heat capacity. For example,
The specific heat capacity of oil is 1.57 j/g. K and for water is 4.18 j/g.K. So, water take a time to increase its temperature by one degree by absorbing more heat while oil will heat up faster by absorbing less amount of heat.
Consider that both oil and water have same mass of 5g and change in temperature is 15 K. Thus amount of heat thy absorbed to raise the temperature is,
For oil:
Q = m.c. ΔT
Q = 5 g× 1.67 j/g K × 15 K
Q = 125.25 j
For water:
Q = m.c. ΔT
Q = 5 g× 4.18 j/g K × 15 K
Q = 313.5 j
we can observe that water require more heat which is 313.5 j to increase its temperature.