11.
What is the chemical formula for methane?
12.
Which gas makes up the majority of Earth's atmosphere?
Explanation:
13.
Which of the following is a halogen element?
14.
What is the chemical formula for hydrochloric acid?
15.
What is the common name for the compound H2O2?
Explanation:
16.
What is the chemical symbol for the element with the atomic number 26?
Explanation:
17.
What is the chemical formula for sodium hydroxide?
18.
Which element is the primary component of natural gas?
19.
What is the chemical symbol for lead?
20.
What is the chemical formula for hydrogen peroxide?