Which of the following elements has three (3) valence electrons?

Mg

K

Al

N

How many molecules of CO2 are equivalent to 112 g CO2? (C=12.01 amu, O=15.9994 amu)

What kind of matter is smoke?

Assume the atomic mass of element X is 22.99 amu. A 17.15-g sample of X combines with 14.17 g of another element Y to form a compound XY. Calculate the atomic mass of Y.

How many unchanged atoms would remain after 3 half-lives if the initial sample had 600 atoms? Explain.

Who determined that the elements needed to be arranged by atomic number instead of atomic mass?

Which of the following lines (of latitude or longitude) would represent by 180 longitude? South Pole Equator Prime meridian North Pole International date line

63Ni decays by a first-order process via the emission of a beta particle. The 63Ni isotope has a half-life of 100. years. How long will it take for 65% of the nickel to undergo decay?

Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product? A. 2C (s) + H2 (g) →C2H2 (g); ΔG∘f=209.2 kJ/molB. N2 (g) + 3H2 (g) →2NH3 (g); ΔG∘f=-33.30 kJ/molC.

How do I find the molar mass of Copper (II) Nitrate?

Describe several main ideas in chemistry