Chemistry Paper 1 Topics Flashcards
What is a mass number?
The mass number is the total number of protons and neutrons in atoms
What is an atomic number?
The atomic number is the total number of protons in an atom
What is the relative mass of a proton?
The relative mass of a proton is 1
What is the relative mass of a neutron?
The relative mass of a neutron is 1
What is the relative mass of an electron?
The relative mass of an electron is very small (1/2000)
What is the relative charge of a proton?
The relative charge of a proton is +1
What is the relative charge of a neutron?
The relative charge of a neutron is 0
What is the relative charge of an electron?
The relative charge of an electron is -1
What is an element?
An element is a substance made up of atoms with the same atomic number
What is an isotope?
Isotopes are atoms with the same number of protons but different numbers of neutrons
What is a compound?
A compound is a substance formed from two or more elements chemically combined together
What is a molecule?
A molecule is a particle containing two or more non-metal atoms bonded covalently
What did the plum pudding model look like?
The plum pudding model was a ball of positive charge containing small negative electrons
What did the nuclear model look like?
The nuclear model showed that mass is concentrated in a positive nucleus with a cloud of electrons
What were the three conclusions of the alpha scattering experiment?
The three conclusions of the alpha scattering experiment were:
- the nucleus is mostly empty space
- the nucleus is dense
- the nucleus is positive
What did the Bohr model show?
The Bohr model showed electrons orbiting a nucleus in fixed shells
What did James Chadwick provide evidence for?
James Chadwick provided evidence that neutrons are neutral particles found in the nucleus
How did Mendeleev order the elements in the periodic table?
Mendeleev ordered the elements in the periodic table by their properties
Why did Mendeleev leave gaps in his periodic table?
Mendeleev left gaps in his periodic table for elements to be placed there when they are later discovered, and also so groups are kept together
What did the discovery of isotopes conclude?
The discovery of isotopes explained why elements cannot be strictly ordered by atomic weight
What does the group number on a periodic table mean?
The group number shows the number of electrons in atom’s outer shell
What does the periodic number on a periodic table mean?
The periodic number shows the number of shells with electrons in
When are metals most reactive?
Metals are most reactive when they lose electrons more easily
Where are metals most reactive on the periodic table?
Metals are most reactive towards the bottom left of the periodic table