How many periods does the periodic table have?

7

18

9

8

A student measures an average molecular weight of 170.2 g/mol with a standard deviation of 1.7. What is the precision of this measurement?

Convert 6.3x1024 molecules of water to liters.

What species is undergoing reduction in the following reaction? NO3 - (aq) + 4Zn (s) + 7OH - (aq) + 6H2O (l) → 4Zn (OH) 42 - (aq) + NH3 (aq)

Which of these equations represents a displacement reaction? Copper + oxygen → copper oxide Zinc + copper sulfate → zinc sulfate + copper Sodium + water → sodium hydroxide + water

0.450 moles of K2SO4 are dissolved in 195.0 mL of water. Calculate the molarity of the solution.

If the average American throws away 4.5 lb of trash each day, and the population of the US is estimated to be 311 million people, calculated the number of metric tons of garbage thrown away in the US each year.

Difference between radical and compound

Water is a produced when 30.0 grams of hydrogen reacts with 80.0 grams of oxygen what is the limiting reagent

How are reactions and products related in a chemical reaction?

Ollie wants to sign up with an online social network called TeensMeet, which other kids at school have joined.