How many valance electrons do most atoms need to have a full shell?

This has been deleted as question wasn't answered on time

Which situation describes a reaction with a percentage yield of 100%? Select one: a. The amounts of reactants initially present are stoichiometric. b. The product is more than the limiting reagent has the potential to produce. C. none of them d.

Two atoms with the same number of protons but a different number of neutrons are

A liquid mixture of milk and flour blended together until smooth is called

Which describes a step in the process of forming an ionic bond? Ametal atom loses electrons and becomes a positive ion. A metal atom gains electrons and becomes a negative ion. Anonmetal atom loses electrons and becomes a negative ion.

Hydrochloric acid is purchased in 12 molar concentrations. If I needed 200 ml of 2.0 molar HCl, how many milliliters of the concentrated solution would I need

Which of the following represents a chemical change? Bending a wire Freezing of water Fireworks exploding Melting of a wax candle

5.00 L of a gas is collected at 100K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure? A. 400 °C B. 127 °C C. 223 °C D. 627°C

Before the initial explosion was the matter hot or cold

Which of the following atoms has seven valence electrons? chlorine (Cl) nitrogen (N) manganese (Mn) oxygen (O)