Download Chapter 11 Vocabulary 1. Atom – the smallest particle into which an

Chapter 11 Vocabulary
1. Atom – the smallest particle into which an element can be divided and still be the same
substance.
2. Electrons – the negatively charged particles found in all atoms.
3. Nucleus – the tiny, extremely dense, positively charged region in the center of the atom.
4. Electron clouds – the regions inside an atom where electrons are likely to be found.
5. Protons – the positively charged particles of the nucleus.
6. Atomic mass unit – the SI unit used to express the masses of particles in an atom.
7. Neutrons – the particles of the nucleus that have no charge.
8. Atomic number – the number of protons in the nucleus of an atom.
9. Isotopes – atoms that have the same number of protons but have different numbers of
neutrons.
10. Mass number – the sum of the protons and neutrons in an atom.
11. Atomic mass – the weighted average of the masses of all of the naturally occurring isotopes of
an element.