Today’s Agenda…10/6

• Bellringer: What group of elements are unreactive? What does this mean?

• Get your clickers!• Compounds and Mixtures

1 day until

fall break!

What do you think?

• True or False (Review questions)– Elements cannot be broken into simpler

substances.– Compounds are made up of two or more atoms of

the same element.– Water is an example of a compound.– Salt is an example of an element.

What do you think?

• True or False (Preview Questions)– Mixtures cannot be separated.– A physical change occurs when compounds are

formed. – The elements in a compound keep their original

properties.– You can see all the parts in a homogeneous

mixture.

Compounds vs. Mixtures

• Compounds and Mixtures are not the same type of substance!

• Today we will investigate the difference between these two substances.

• We will investigate…– Their composition– How they are joined– Their properties– If and how they can be separated– Examples

Composition

• Mixture– Varies– You can change the

amount of each substance in a mixture

• Compound– Definite– You cannot change the

amount of each element in a compound

Joined

• Mixture– A physical change occurs

when substance come together

– The substances are NOT chemically joined together

• Compound– A chemical change

occurs when substance come together

– The substances are chemically joined together

Separation

• Mixture– Each substance is easily

separated from the mixture

– Sorting, sifting, filtering, evaporation

• Compound– Can only be separated

into elements using chemical reactions

Properties

• Mixture– Each substance keeps its

own properties

• Compound– The compound has

different properties than the elements it contains

Examples

• Mixture– Air– Salt water– Soup

• Compound– Water– Salt– Carbon dioxide

Chex Mix vs. Salt Water

• What is the difference?• Which one is easier to separate?• Chex mix is a heterogeneous mixture while

salt water is a homogenous mixture or solution

Homogeneous vs. Heterogenous

• Homogeneous mixture - “the same throughout”, meaning you cannot see the different parts in the mixture, like salt water or air

• Heterogeneous mixture – you can see the different parts in the mixture, like pizza and vegetable soup

What did you learn?

• True or False – Mixtures cannot be separated.– A physical change occurs when compounds are

formed. – The elements in a compound keep their original

properties.– You can see all the parts in a homogeneous

mixture.