"Chapter 1 Chemistry": HTML5 Crossword

Across

2. ________ pollutants are harmful substances that form when primary pollutants react with each other or with water vapor. (9,0)
4. PM=________Matter. (11,0)
6. Metal is a good __________ of electricity and heat. (9)
7. 78% of air is ________. (8)
8. _______= Intrinsic health hazard. (8,0)
9. What is the amount of substance encountered? (8,0)
11. Group 8A is full of _______ gases. (5)
12. Air is a _________. (7)
13. The horizontal columns on the periodic table are called_________? (7)

Down

1. Automobile and coal fire electric plants are two causes of __________ pollution. (13,0)
3. Carbon ________ is the silent killer. (8)
5. Air is composed of 2 elements and 8________. (9)
10. ______are composed of one atom. (8)