Kaupapa: 16 / 05 Tuesday Define “compound” Explain why compounds have different properties to the elements they are formed from

Do you remember? Define “element” Atoms are made of three things. What are they? How many electrons, protons and neutrons are there in an aluminium atom?

Question: What is the chemical name of “salt”? Answer: Sodium Chloride (NaCl)

Sodium Metal

Chlorine Gas

+ = ???

Elements and Compounds Elements are made up of only one type of atom. Compounds are made up of two or more types of atoms which are chemically combined, created by a chemical reaction.

Demo: Aluminium + Iodine

Practical: Making a compound Aim: to produce a compound by chemically combining two elements – iron and sulfur Method: <diagram here> Observation:

Properties Iron Sulfur Compound (Iron Sulfide) Magnetic Non-magnetic Sinks in water Floats on water Black Yellow

Properties Iron Sulfur Compound (Iron Sulfide) Magnetic Non-magnetic Sinks in water Floats on water Black Yellow Brown

Q: Why do compounds have different properties from the elements from which they are made? A: When elements are chemically joined (to become a compound), the atoms lose their individual properties and have different properties as their bonds and structure are changed.

Demo: Zinc + Sulfur

What have we learnt today? Define the term “element” Define the term “compound”