atomic structure KO Flashcards
What are atoms?
Atoms are tiny particles that everything is made of. They have a radius of about 0.1 nanometers
What does the nuclear model of an atom show?
An atom has a nucleus that is surrounded by electrons in shells.
What is the plum pudding model?
A sphere of positive charge with electrons scattered throughout.
What does the nucleus contain?
Protons and neutrons
What is meant by the term ‘element’?
An element contains only one type of atom and elements can be found on the periodic table.
What is the charge and relative mass of a proton
+1 and 1
What is the charge and relative mass of a neutron
0 and 1
What is the charge and relative mass of an electron
-1 and 1/2000
Why do atoms have no overall charge?
They have the same number of positive protons and negative electrons
What is meant by ‘the nuclear symbol’ of an atom
The nuclear symbol is the chemical symbol and the two number by it.
Define atomic number
The number of protons in the nucleus
Define mass number
The number of protons plus the number of neutrons in the nucleus
What is an isotope?
An element with the same number of protons but a different number of neutrons. The atomic number is the same, but the mass number can vary.
What is the equation to calculate relative atomic mass (Ar)
Ar = sum of (isotope abundance x isotope mass number)
Sum of abundances of all the isotopes
What are compounds?
Compounds are formed when elements react and atoms combine. Compounds are made up of two or more different elements that are chemically combined
What is a molecule?
A molecule consists of two or more elements that are chemically combined.
Compounds are represented by formulae. What does the formula of a substance show.
The formula shows the ratio of the elements in the compound e.g. CaCO3 has 1 calcium, 1 carbon and 3 oxygen atoms in it. It has 5 atoms in total and 3 elements in i
What is a mixture?
A mixture is made up of separate substances that are not chemically combined e.g. air, sand and salt,
To separate a solid in a liquid?
Filtering
To separate (two or more) liquids?
Distillation or fractional distillation for more liquids.
To remove a soluble product from a solution?
Evaporation and crystallisation
To separate a mixture of coloured liquids?
Chromatography
In Chromatography, is the starting line drawn in pen or pencil?
Pencil
What two pieces of equipment is used during filtration?
Funnel and filter paper
