Be sure to answer all parts. Write a balanced equation for each reaction. Do not include states of matter to your equation.
H2 + O2 H20

2H₂ + O₂       →     2H₂O

Explanation:

Chemical equation:

H₂ + O₂       →     H₂O

Balance chemical equation:

2H₂ + O₂       →     2H₂O

Step 1:

H₂ + O₂       →     H₂O

Left hand side                     Right hand side

H = 2                                    H = 2

O = 2                                    O = 1

Step 2:

H₂ + O₂       →     2H₂O

Left hand side                     Right hand side

H = 2                                    H = 4

O = 2                                    O = 2

Step 3:

2H₂ + O₂       →     2H₂O

Left hand side                     Right hand side

H = 4                                    H = 4

O = 2                                    O = 2

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

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).