2. Atoms & Elements

If an atom has 35 protons in its nucleus, which element is it?

Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a neutral calcium atom must have:

In a water molecule (H_2O), which atom carries a partial negative charge?

Which subatomic particle can be used to identify an atom as belonging to a specific element?

Which statement best describes the distribution of charge in an atom?

Which part of an atom is mostly empty space?

Which of the following is the number of protons in a sulfur atom?

What is the mass number for an atom of barium containing 56 protons and 82 neutrons?

Which subatomic particle determines the identity of an element?

In which part of the atom is the neutron located?

Which of the following is considered the smallest basic unit of matter?

How many Cl2O molecules of different masses (isotopologues) naturally exist due to the presence of stable isotopes of chlorine and oxygen?

Which term describes the region surrounding the nucleus where electrons are most likely to be found?

Which of the following best describes the electric charge of a single proton?

Which of the following best describes an element?