3. Which element is most important for growing crops?

a. carbon dioxide

BA

b. hydrogen

C. calcium

d. nitrogen

4. Who discovered how to manipulate equilibrium systems?

What type of reaction is the decay of carbon-14

Which statement can explain why oil does not dissolve in water?

Label each of the components in the equation below what type of reaction

A student obtains the following dа ta: Mass of empty, dry graduated cylinder: 20.134 g Volume added of NaCl solution: 6.744 mL Mass of graduated cylinder NaCl solution: 33.393 g What is the density of the solution?

Chemists can use moles to calculate: A. How much of the products are needed and how much reactant will be made. B. How much product will be made, but not how much of the reactants are needed. C.

In each row, the box under the compound that can reasonably be expected to be more acidic in aqueous solution, e. g. have the larger Ka. H2 TeO4 H2TeO3 HClO2 HClO HClO HBrO

You are doing chores to earn your allowance. For each chore you do, you earn $3.00. What is the independen variable?

As the solar system formed, most of its mass became concentrated in one part of it. What is that that part?

In the scientific process what is the purpose of the experiment A-to test the hypothesis B-to prove the hypothesis true C-to prove the hypothesis fake D-to turn the hypothesis into a theory

A sample of an unknown substance has a mass of 0.158 kg. If 2,510.0 J of heat is required to heat the substance from 32.0°C to 61.0°C, what is the specific heat of the substance?