Additional science

Additional science

1. Atoms

   • At the centre of every atom is a nucleus containing protons and neutrons.
   • All atoms of the same element have the same number of protons.This number is used to arrange the elements in the periodic table,beginning with hydrogen which only has one proton
   • Electrons are contained in shells around the nucleus. The total number of electrons is always the same as the number of protons in the nucleus

2. Atomic number

   • The atomic number of an atom is the number of protons it contains. All the atoms of a certain element have the same atomic number.
   • The atoms of different elements have different numbers of protons

3. Transition elements

   • Transition means "an in between state".
   • They have high density
   • Have high melting points
   • They mostly form coloured compounds
   • They are less reactive than group 1 or group 2 metals

4. Isotopes

   • Isotopes are an element that has the same number of protons and electrons but have a different number of neutrons