2. Atoms & Elements

What is the charge of the nucleus of element 89 (actinium)?

How many neutrons are present in an atom of iridium (Ir) with a mass number of 193?

Why is mercury difficult for us to see in its atomic form under normal conditions?

Can you determine the exact number of neutrons in an atom by looking only at the periodic table?

How many protons are present in a neutral atom of manganese?

How many protons are present in a single atom of sodium (Na)?

In a typical covalent compound, how many single covalent bonds can a nitrogen atom form?

Which term refers to the amount of matter in an object?

Which of the following are the very small particles that make up matter?

In the atomic symbol _{17}^{35}Cl_, which number represents the atomic number and which represents the mass number?

Which of the following particles lacks a nucleus?

Which element has 3 valence electrons and 4 energy levels?

Which of the following pure substances can be classified as an element?

Which term describes the group of protons and neutrons located at the center of all atoms?

Which of the following best describes the difference between an atom and a molecule?