If element X has 99 protons, how many electrons does it have

Identify the indicated sets of protons as unrelated homotopic

2H2S (g) 2H2 (g) + S2 (g) Kc = 1.67 * 10 ^-7 at 800 C A 0.500 L reaction vessel initially contains 0.0125 mol of H2S at 800 C. Find the equilibrium concentrations of H2 and S2.

How many grams of h3po4 are in 417 ml of a 2.90 m solution of h3po4?

Stuck stupid science homework. anyone know answers?

Checking the dining areas of an eating establishment for evidence of flaking paint, broken light bulbs, and wood damage will reduce the chances of:

What is an isotope? Give an example of an element with isotopes.

Consider the reaction between liquid water and aqueous magnesium nitride to form solid magnesium oxide and ammonia gas. If magnesium nitride is present in excess, how many moles of water are needed to form 9.17*1023 ammonia molecules?

The properties of elements are arranged by ... A. mass numbers B. atomic masses C. atomic radii D. atomic numbers

When a tire is inflated with air is it a chemical or physical change?

Which isotope is used to date ancient artifacts such as fossils? carbon-12 carbon-14 uranium-238 oxygen-16