In a covalent bond, two atoms are held together by the attraction between what?

Suppose you find a rock originally made of potassium-40, half of which decays into argon-40 every 1.25 billion years. You open the rock and find 7 atoms of argon-40 for every atom of potassium-40. How long ago did the rock form?

What happens to matter if we add or take away energy

Describe an open system. What's an open system?

Which of the following represents the chemical reaction of hydrazine and hydrogen peroxide to produce nitrogen and water?

If the amount of solute present in a solution at a given temperature is less than the maximum amount that can dissolve at that temperature, the solution is said to be

How are natural polymers and synthetic polymers similar? A) Both are made up of phosphates and organic bases B) Both serve important roles in producing amino acids C) Both are made up of monomers that are linked by covalent bonds

How can the solubility of a solution be increased? By increasing the temperature. By decreasing the temperature. By increasing the amount of solvent added. By decreasing the amount of solvent added.

Read the scenario. Ammonia is obtained from a reaction between nitrogen and hydrogen gases. The mole ratio between hydrogen gas and nitrogen gas is 3 to 1, and the mole ratio between ammonia and hydrogen gases is 2 to 3.

Transmutation is the process of transforming one element into another through nuclear reactions. What will be the nuclide produced when Cf-249 is bombarded with C-12? Four neutrons are also produced by the reaction.

State the formula for density in words and mathematical symbols.