principles of chemistry - atomic structure

Question 1

what is an atom?

Answer 1

the smallest particle of a chemical element that can exist. its made up of protons, neutrons and electrons

Question 2

what is a proton?

Answer 2

a particle in an atom. it is heavy and positively charged

Question 3

what is a neutron?

Answer 3

a particle in an atom. it is heavy and neutral

Question 4

what is an electron?

Answer 4

a particle in an atom. it has hardly any mass and is negatively charged

Question 5

what is a molecule?

Answer 5

a group of atoms joined together.

Question 6

what is in the nucleus of an atom?

Answer 6

• its in the middle of the atom
• it contains protons and neutrons
• has a positive charge
• almost the whole mass of it is in the nucleus

Question 7

what are isotopes?

Answer 7

different atomic forms of the same element, which have the same number of protons but different numbers of neutrons

Question 8

how to calculate relative atomic mass

Answer 8

(isotope mass x isotope abundance) x 100

Question 9

what is the atomic number?

Answer 9

the amount of protons in the nucleus of that element. it is the number below the element on the periodic table

Question 10

what is the mass number?

Answer 10

the amount of protons and neutrons in the nucleus of that element. it is the number above the element on the periodic table.