Topic 1 Flashcards
(23 cards)
What are alkali metals?
The elements in Group 1 of the periodic table.
What is an atom?
The smallest part of an element that can exist. All substances are made up of atoms.
What is an atomic nucleus?
Positively charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it.
What is atomic number?
The number of protons in the nucleus.
What is chromatography?
A separation technique used to separate a mixture of chemicals by distributing the components between two phases.
What is a compound?
A substance made up of two or more types of atoms chemically combined together.
What is crystallisation?
A separation technique used to produce solid crystals from a solution by evaporating the solvent.
What is displacement in chemistry?
A chemical reaction in which a more reactive element displaces a less reactive element from its compound.
What is an electron?
Negatively charged subatomic particle which orbit the nucleus at various energy levels. Very small relative mass (negligible).
What is an electron shell?
Different energy levels in atoms occupied by electrons.
What is an element?
A substance made up of only one type of atom.
What is filtration?
A separation technique used to separate solids from liquids.
What is fractional distillation?
A method of separating a mixture of substances according to their different boiling points.
What does a group represent in the periodic table?
The columns of the periodic table represent different groups of elements. Elements with similar properties are in the same group.
What are halogens?
The elements in Group 7 of the periodic table.
What is an ion?
An atom or molecule with an electric charge due to the loss or gain of electrons.
What is an isotope?
Atoms of the same element with the same number of protons but a different number of neutrons.
What is mass number?
The total number of protons and neutrons in the nucleus.
What are metals?
Elements that react to form positive ions. Found to the left and towards the bottom of the periodic table.
What is a mixture?
A mixture consists of two or more elements or compounds not chemically combined together.
What is a neutron?
Neutral subatomic particle present in the nucleus of the atom. Relative mass of 1.
What are noble gases?
The elements in Group 0 of the periodic table.
What are non-metals?
Elements that react to form negative ions. Found towards the right and top of the periodic table.
