A substance that speeds up the rate of a chemical reaction is called

a. a catalyst.

b. a lipid.

c. a molecule.

d. an element.

Which characteristic surface of the moon contains the same rock as the ocean floor? A. craters B. terrae C. maria D. regolith

How can you tell the difference between non metals from metals on the periodic element chart with no colors

If there are 11 protons and 10 neutrons in the nucleus of an atom, what is the atomic number?

How many atoms are in 0.075 mol of helium

11. What happens to atmospheric pressure as a person rises in altitude? A. It's unaffected by changes in altitude. OB. It decreases. C. It changes based on the time of year. D. It increases.

2. What type of bond holds together nitrogen atoms? a. Single Bond b. Double Bond c. Triple Bond d. no bonds hold nitrogen together

Charge on monatomic ions: a) I b) Sr c) K d) N e) S f) In

What is the actual yield if only 50% of a theoretical yield of 200g is formed. A.) 100g B.) 75g C.) 120g D.) 140g

Hydrogen sulfide gas and sulfur dioxide gas react to form solid sulfur and water. If 10.0g of gaseous hydrogen sulphide is mixed with 10.0g of gaseous sulfur dioxide, how many grams of solid sulfur can form?

What do scientists do during data collection? O A. Analyze information to form a summary B. Gather information during an experiment C. Observe and ask scientific questions O D. Design an experiment to test a hypothesis