11:1 How has the Daltons atom model changed?
Dalton said incompressible, can't be created or destroyed. Then discovered the electron. Gold foil experiment revealed positively charged nucleus. Bohr model showed the electrons organised in electron shells
21:2 Describe the structure of an atom
Nucleus containing protons and neutrons surrounded by electron shells containing electrons
31:3 Relative charge of a proton
+1
41:3 Relative mass of a proton
+1
51:3 Relative charge of a neutron
0
61:3 Relative mass of a neutron
1
71:3 Relative charge of an electron
-1
81:3 Relative mass of an electron
1/1835 (negligible)
91:4 Why do atoms contain equal numbers of protons and electrons?
Protons are positive and electrons are negatively charged so they cancel each other out
101:5, 1:6Describe the size and mass of the atom and nucleus
The nucleus of the atom is extremely small compared to the overall size of the atom however most the mass is concentrated in the nucleus
111:7 Define mass number
the total number of protons and neutrons in a nucleus.
121:8 What subatomic particle is unique to each element
protons
131:9 Define isotope
atoms of the same element with the same number of protons but different number of neutrons in their nucleus
141:10 How to calculate the number of protons
equals the atomic number
151:10 How to calculate the number of neutrons
mass number - atomic number
161:10 How to calculate the number of electrons
equals number of protons / atomic number
171:11 Why aren't some relative atomic masses whole numbers?
Because the atomic number takes into account all the isotopes, its average can be a decimal
181:12 How to calculate the relative atomic mass
total mass of the atoms/the number of the atoms