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
How do metals get full outer shells?
Metals get full outer shells by losing electrons
How do non-metals get full outer shells?
Non-metals get full outer shells by gaining or sharing electrons
When are non-metals most reactive?
Non-metals are more reactive when they gain electrons more easily
Where on the periodic table are non-metals most reactive?
Non-metals are most reactive towards the top right of the periodic table
What are the properties of metals?
The properties of metals are that they are shiny, strong but malleable, have high boiling and melting points, are good electrical and thermal conductors
What are the properties of non-metals?
The properties of non-metals are that they are dull, brittle, have low melting and boiling points, are poor conductors
What are the properties of the transition metals found in the centre of the periodic table?
Transition metals have multiple ions, form colourful compounds, can be good catalysts
What happens to alkali metals as you go down the group?
As you go down the group of alkali metals, reactivity increases, melting and boiling point decreases and relative atomic mass increases
What are the properties of alkali metals?
Alkali metals are more reactive than other metals, are less dense and softer than other metals and has lower melting points
Metal + Water > ?
Metal + Water > Metal hydroxide + hydrogen
Metal + Chlorine > ?
Metal + Chlorine > Metal chloride
Metal + Oxygen > ?
Metal + Oxygen > Metal oxide
What happens to a reaction with water as the reactivity increases?
The reaction becomes more vigorous and explosive as a reaction with water increases
What is the appearance of fluorine?
Fluorine appears as a yellow gas
What is the appearance of chlorine?
Chlorine appears as a dense green gas
What is the appearance of bromine?
Bromine appears as a volatile red-brown liquid
What is the appearance of iodine?
Iodine appears as a dark grey solid or purple vapour
What happens as you go down group 7?
As you go down group 7, reactivity decreases, melting and boiling points increase and the relative mass increases
What do halogens exist as?
Halogens exist as diatomic molecules - two atoms joined by a covalent bond
What are ions?
Ions are charged particles made when electrons are transferred
What do metals do in order to get a full outer shell? What charge does this make them?
Metals lose electrons to form positive +1 ions if in group 1, and positive +2 ions if in group 2
What do non-metals do in order to get a full outer shell? What charge does this make them?
Non-metals gain electrons to form negative -1 ions if in group 7, and negative -2 ions in group 6
What is ionic bonding?
Ionic bonding is the electrostatic attraction between oppositely charged ions. Ionic bonding occurs between positive metal ions and negative non-metal ions
What are the properties of ionic compounds?
The properties of ionic compounds are:
- Giant ionic lattice structure
- High melting and boiling points
- Conducts electricity only when molten or dissolved - so ions are free to move and carry electric charge
What are the limitations of the 3D model of compounds?
The 3d model is not to scale, there are gaps between ions and only the outer layer of the compound can be seen
What is a covalent bond?
A covalent bond is a shared pair of electrons between two non-metal atoms
What do molecular formulas show eg NH3
Molecular formulas show you how many atoms of each element are in a compound
What are the negatives of using a dot and cross diagram?
Dot and cross diagrams don’t show the relative size of atoms or their arrangement in space
What are the negatives of ball and stick diagrams?
Ball and stick diagrams don’t show which atoms the electrons in the bonds come from
What are the properties of simple molecular substances?
The properties of simple molecular substances include low melting and boiling points (mostly gas and liquid at room temperature), and doesn’t conduct electricity as there are no charged particles
What are the properties of diamond?
Diamond is very hard, has a high melting point, doesn’t conduct electricity
What are the properties of graphite?
Graphite is soft, slippery, have high melting points and can conduct electricity and thermal energy
What are the properties of graphene?
Graphene is strong, light and conducts electricity
What are the properties of fullerenes?
Fullerenes have hollow shapes and rings of atoms
What are the features of metallic bonding?
Metallic bonding is a giant regular structure, held together by strong electrostatic attractions between metal atoms, has delocalised outer shell electrons that are free to move