An atom is electrically neutral because_______________.

Distillation process cannot be used in separating a mixture of __________.

Hydrogen peroxide is used as a bleaching agent and a disinfectant. If the chemical formula of hydrogen peroxide is , what is its empirical formula?

The mass number of a certain atom is 64 and the number of neutrons is 35. How many electrons does the atom have?

The electrical charges in atom are located in___________.

Two isotopes of the same element may have different ____________.

Which of the following statement is TRUE?

It is the process of changing solid to gas.

It is the ability of a substance to react with other substances.

It is the ratio of the mass of an object to the volume it occupies.

It states that different samples of the same compound always contain their constituent elements in the same proportion by mass.

It is the sum of number of protons and neutrons in the nucleus.

It is the ratio of the average atomic mass of an atom to one atomic mass unit.

Protium, deuterium, and tritium are examples of ________________.