An element has atomic number 10 and an atomic mass of 20. How many neutrons are in the atom of this element?

A. 10

B. 20

C. 30

D. 0

E. 200

In water, HCN is a weak acid with pKa = 9.6. a. Calculate the the Ka and the [H+] in a 0.15 M solution of HCN. b.

Consider the reaction between HCl and O2: 4HCl grams + O2 - 2 H2O liquid + 2 Cl2 grams When 63.1 grams of HCl react with 17.2 g of O2, 49.3 grams of Cl2 are collected. What is the limiting reactant?

The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 4000 years? ... ?

the maximum number of electrons in each type of sublevel (s, p, d, and f, respectively

Can a element be decomposed by chemical means

What information does a net ionic equation give that a complete ionic equation does not show

What is the molality of a solution containing 4.0 moles of solute in 3.2 kg of solvent? Round to the nearest tenth. Don't forget the units.

What is the name of a binary compound made up of lithium and chlorine?

A scientist in London and a scientist in California both conducted independent investigations that produced similar results.

When magnesium combines with oxygen, the reaction involves a. a conversion of protons into electrons. b. sharing of electrons between Mg and O. c. transfer of electrons from Mg to O. d. transfer of electrons from O to Mg.