Science Chapter 2: Atoms and Molecules
Atom
Definition: Smallest particle of an element and matter, non living and living. Even we humans are made of atoms. An Atom is made up of a nucleus in the centre and electrons orbiting around it.
An atom is made up of three parts, the protons, neutrons & electrons. The protons and neutrons make up the atom's nucleus, and also makes up the atom's mass.
Protons contain a positive charge and neutron contains a neutral or no charge. Thus, the nucleus has a positive charge. The electrons contain a negative charge will orbit about the nucleus at high speeds. Also, an atom is always neutral because it has the same amount of electrons and protons.
Ions
Sometimes, due to chemical reactions, the electrons in the atom become lost or an atom gains an electron from another atom. When this happens we call that charged atom an Ion. We call positive Ions CatIons and negative Ions AnIons. The amount of electrons lost or gained differs with each atom.
Molecules
Definition: Molecules are made up of two or more atoms chemically joined together. They exist in the forms of both compounds and elements. Each molecule can only be made up of a fixed number of a certain kind of atom only. For example: An Oxygen molcule has to be made up of two oxygen atoms.
Elements and Compounds
Elements are made of two or more of the same kind of atom chemically joined together. Compounds are made of two or more different atoms chemically joined together. There are at least two chemical symbols that represent them since they are made of two or more atoms.
OK!!!!!!! DONE!!!!!! yay!!!! Woots... Hahax... Later going to do chapter 3... 4 tmr bah...
