What does this equation, 2 c(s) + o 2(g) ® 2 co(g), tell us?
a) the number of atoms of each kind in reactants and products is the same
b) carbon monoxide (co) is a product
c) two atoms of carbon undergo reaction
d) all of these

D. All of these.

Explanation:

For an equation to be balanced the number of atoms of each kind in the reactants and the products should be the same.

Then from this equation, CO  is a product.

Last, two carbon atoms undergo reaction with the oxygen molecule for complete reaction to occur. Each atom combines with one oxygen atom.

D) All of these

Explanation:

Reactant side (Left side)  Element    Product side (Right side)

2                                                   C                                      2

2                                                   O                                      2

Balanced!!!

Balancing is making the number of atoms of each element same on both the sides  (reactant and product side).

To find the number of atoms of each element we multiply coefficient × subscript  

For example contains  

5 × 1 = 5 ,Ca atoms and

5 × 2 = 10, Cl atoms  

If there is a bracket in the chemical formula

For example we multiply coefficient × subscript × number outside the bracket.......... to find the number of atoms  (Please note: 3 is the coefficient, and if there is no number given then 1 will be the coefficient )

So

3 × 3 = 9 , Ca atoms  

3 × 1 × 2 = 6, P atoms  

3 × 4 × 2 = 24, O atoms are present.

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .

c is the answer because when something is left after something evaporates that shows the chemical change.