Atomic Structure

Question 1

charge of proton

Answer 1

positive

Question 2

charge of neutron

Answer 2

neutral

Question 3

charge of electron

Answer 3

negative

Question 4

protons and neutrons in an atom

Answer 4

equal number of protons and neutrons

Question 5

nucleus

Answer 5

protons and neutrons

Question 6

structure of the atom

Answer 6

central, positively charged nucleus containing protons and neutrons (positive and negative charge)
nucleus is surrounded by electrons in electron shells

Question 7

atomic number

Answer 7

number of protons

Question 8

mass number

Answer 8

number of protons and neutrons combined

Question 9

isotope

Answer 9

atoms of the same element with the same number of protons but a different number of neutrons - same element, but with different mass numbers

Question 10

relative atomic mass

Answer 10

average mass of all the isotopes of an element, taking into account their relative abundance, compared to one-twelfth of the mass of a carbon-12 atom

Question 11

states of matter

Answer 11

• solids
• liquids
• gases

Question 12

structure of solids

Answer 12

• particles in lattice
• fixed shape and volume
• cannot be compressed

Question 13

structure of liquids

Answer 13

• particles in loose lattice
• fixed volume, but can flow and change space
• occupy slightly more space than solids
• cannot be compressed

Question 14

structure of gases

Answer 14

• no fixed shape or volume
• can be easily compressed

Question 15

solid —> liquid

Answer 15

melting

Question 16

liquid —> solid

Answer 16

freezing

Question 17

liquid —> gas

Answer 17

boiling/evapourating

Question 18

gas —> liquid

Answer 18

condensing

Question 19

find number of electrons

Answer 19

mass number - number of protons

Question 20

John Dalton’s contribution

Answer 20

developed the idea of the atom as something that makes up everything, and couldn’t be divided

Question 21

JJ Thomson’s contribution

Answer 21

discovery of the presence of electrons
plum pudding model shows the atom as a ball of positive charge with negative electrons embedded in it

Question 22

Ernest Rutherford’s contribution

Answer 22

designed experiment to prove the plum pudding model - gold foil experiment that passed alpha particles through the foil - some particles went through but some reflected off
nuclear model
the mass of an atom is concentrated at its centre,
Rutherford suggests new model - the nuclear model
- the mass of an atom is concentrated at centre of nucleus
- positively charged nucleus

Question 23

James Chadwick’s contribution

Answer 23

discovery of the presence of neutrons - development of the atomic structure model used today