atoms elements and compounds
Chemistry revision
Atoms elements and compounds
Atom-the smallest part of an element that can still be recognized as an element
Element-a substance made up of only one type of atom. An element cannot be broken down chemically into any simpler substance
Nucleus-middle of the atom, which contains protons and neutrons
Electron-tiny particle, which surrounds the nucleus with a negative charge
Compound-when two elements react and combine together which contain more than one element. There are about 100 different elements from which all substances are made
All substances are made of atoms
Atomic structure
Proton-is a particle at the centre of the nucleus with a positive charge
Neutron-a particle at the centre of the nucleus with a neutral charge
Atomic number-the number of protons in an atom, which is equal to the number of electrons, which is also called the proton number
Mass number-the total number of particles in the nucleus of an atom so it is the number of protons plus the number of neutrons
The nucleus at the centre of the atom contains two types of particle called protons and neutrons.
Atoms are neutral because the number of protons is equal to the number of electrons and their charges are equal and opposite (proton +1 and electron -1)
The arrangement of electrons in atoms
Energy level- an area in an atom around its nucleus where the electrons are found
Electronic structure-a set of numbers to show the arrangement of electrons in their shells for example the electronic structure of a potassium atom is 2,8,8,1
Each electron in an atom is in an energy level. Energy levels can be represented
As shells
Elements in the same group of the periodic table have the same number of electrons in their highest energy level e.g. group 1 elements have one electron in their highest energy level
Group1 elements include lithium sodium and potassium. These elements react quickly with water and oxygen.
Forming
Atoms elements and compounds
Atom-the smallest part of an element that can still be recognized as an element
Element-a substance made up of only one type of atom. An element cannot be broken down chemically into any simpler substance
Nucleus-middle of the atom, which contains protons and neutrons
Electron-tiny particle, which surrounds the nucleus with a negative charge
Compound-when two elements react and combine together which contain more than one element. There are about 100 different elements from which all substances are made
All substances are made of atoms
Atomic structure
Proton-is a particle at the centre of the nucleus with a positive charge
Neutron-a particle at the centre of the nucleus with a neutral charge
Atomic number-the number of protons in an atom, which is equal to the number of electrons, which is also called the proton number
Mass number-the total number of particles in the nucleus of an atom so it is the number of protons plus the number of neutrons
The nucleus at the centre of the atom contains two types of particle called protons and neutrons.
Atoms are neutral because the number of protons is equal to the number of electrons and their charges are equal and opposite (proton +1 and electron -1)
The arrangement of electrons in atoms
Energy level- an area in an atom around its nucleus where the electrons are found
Electronic structure-a set of numbers to show the arrangement of electrons in their shells for example the electronic structure of a potassium atom is 2,8,8,1
Each electron in an atom is in an energy level. Energy levels can be represented
As shells
Elements in the same group of the periodic table have the same number of electrons in their highest energy level e.g. group 1 elements have one electron in their highest energy level
Group1 elements include lithium sodium and potassium. These elements react quickly with water and oxygen.
Forming