ELEMENTS, Atoms, Compounds and Molecules By Terry Gunning
Elements Elements are made up of atoms. All the elements are listed on the periodic table. Elements are purely one substance.
Atoms An atom is made of protons, neutrons and electrons. Atoms make up elements. The amount of protons, neutrons and electrons defines what element it is.
Metals and Non Metals A metal has high electrical and thermal conductivity. Metals are usually shiny, solid at room temperature, ductile and malleable. Metals normally have 1-3 electrons in their outer shell. Non Metals are poor conductors of heat and electricity. They can be solid, liquid or gas at room temperature. Non metals have 4-8 electrons in their outer shell.
Periodic Table The periodic table shows all the elements and their atomic number.
Compounds A compound is a substance consisting of two or more different elements that can be separated by a chemical reaction. Water is a compound made up of two hydrogen and one oxygen atom.
Chemical Reactions A chemical reaction is when two or more elements interact and create a new compound. Some chemical reactions are spontaneous and some are non-spontaneous needing input from some sort of energy (electricity, heat or light).
Identifying Chemical Reactions A chemical reaction is when two elements combine. Some times a bye product can be created like a gas.
Chemical and Physical Changes A chemical change is when the substance is changed chemically like metal rusting. A physical change is when a substance changes shape or form.
Reaction Rate and Factors Affecting It Reaction rate can be accelerated with heat and decreased in the cold.