Atomic Theory

Question 1

Nucleus

Answer 1

central part of an atom, made up of protons and neutrons; roundish structure inside a cell that acts as the control centre for the cell. Plural = nuclei.

Question 2

Electrons

Answer 2

negatively charged, very light particles in an atom. Electrons move around the nucleus of the atom.

Question 3

Protons

Answer 3

: positively charged particles found in the nucleus of an atom

Question 4

neutrons,

Answer 4

particles with no electrical charge that are found in the nucleus of an atom

Question 5

Isotope

Answer 5

atoms of the same element that differ in the number of neutrons in the nucleus

Question 6

Stable

Answer 6

describes a nucleus that does not change spontaneously. The protons and neutrons in the nucleus are held together strongly.

Question 7

Unstable

Answer 7

describes an atom in which the neutrons and protons in the nucleus are not held together strongly

Question 8

Radioisotopes

Answer 8

a radioactive form of an isotope