Which one of the following elements does not exist as a diatomic molecule in nat

3.Which one of the following elements does not exist as a diatomic molecule in nature?

(a) hydrogen (b) nitrogen (c) fluorine (d) neon

For questions 4. and 5., consider the following reaction:

4 Al (s) + 3 O2 (g) ⇒ 2 Al2O3 (s)

4. The reaction can be classified as which one of the following types?

(a) precipitation (b) decomposition (c) synthesis (d) double displacement

5. How many moles of Al2O3 can be produced from the reaction of 10.0 g of Al and 19.0 g of O2?

(a) 0.581 mol (b) 0.371 mol (c) 0.185 mol (d) 0.396 mol

6. What volume of 12.0 M HCl is required to make 75.0 mL of 3.50 M HCl?

(a) 21.9 mL (b) 0.560 mL (c) 257 mL (d) 75.0 mL

7. A fish tank holds 1.029 yd3 of water. What is this volume in cubic meters given that 1 m = 1.093 yd?

(a) 1.062 m3 (b) 0.9414 m3 (c) 1.125 m3 (d) 0.7881 m3

8. Which one of the following is a strong acid?

(a) HNO3 (b) CaSO4 (c) NH3 (d) NaOH

For questions 9. and 10., consider the heating curve of a hypothetical substance:

9. What is the boiling point of the substance?

(a) 0°C (c) 12°C

(b) −50°C (d) 75°C

10. What state of matter is the substance at 50°C?

(a) gas (c) solid

(b) liquid (d) not enough information