Changes to

Materials

What is a Solid?

(1)

(2)

(3)

A piece of wood A tennis ballA diamond

A solid has definite shape and volume.

What is a Liquid?

A liquid has no definite shape, but does have definite volume.

(4)

What is a Gas?

Sulphur dioxide

A gas has no definite shape or volume.

(5) (6)Carbon dioxide

Changes to materials can be reversible; such as melting, freezing or evaporating.

(7)

An ice cube melting

Changes to materials can be irreversible; such as burning, rusting or cooking.

Ash left over from burnt paper(8)

Gases of carbon dioxide

What is Physical Change?

Water may freeze, melt or evaporate, but it is always water – it has only physically changed.

(9)

Different Physical Changes

(10)(11)

(12) (13)

They have changed shape, but have not changed chemical substances.

What is Chemical Change?

A kernel of corn, if heated changes into popcorn. It cannot be changed back – it has chemically changed.

(14)

(15)

Different Chemical Changes

(16)(17)

They have changed chemically and cannot be changed back.

(19)(18)

Misconceptions

(18)

• Solids melt, not dissolve.• Water evaporates, not disappears.

Solids dissolve?

Water disappears?

Reversible changes to Recycled Materials

Recyclable materials can be remade into another product without making a chemical change.

(22)

(20)

(19)

(21)

•Physical changes to materials are reversible.

•Chemical changes to materials are irreversible.

References:

Image References:

Number 1 – Microsoft 2007 Clipart, retrieved from document clipart “wood”, March 5, 2011Number 2 – Microsoft 2007 Clipart, retrieved from document clipart “diamond”, March 5, 2011Number 3 – Microsoft 2007 Clipart, retrieved from document clipart “tennis ball”, March 5, 2011Number 4 – “water pouring” retrieved March 5, 2011 from http://www.witweightloss.com/fat-burning-foods/top-five-benefits-water-you-should-take-advantage.htmlNumber 5 – “volcano” retrieved March 5, 2011 from http://volcanoes.usgs.gov/images/pglossary/VolcGas.phpNumber 6 – “smoke stack” retrieved March 5, 2011 from http://www.treehuggerusa.com/greenhouse-gases/index.htmlNumber 7 – Microsoft 2007 Clipart, retrieved from document clipart “ice melting”, March 5, 2011Number 8 – “burning paper” retrieved March 5, 2011 from http://www.dreamstime.com/stock-images-burning-paper-image17090564Number 9 – “water cycle” retrieved March 5, 2011 from http://www.urbanrivers.org/water_cycle.htmlNumber 10 – “piece of wood” retrieved March 5, 2011 from http://www.istockphoto.com/stock-photo-4249015-single-piece-of-wood.phpNumber 11 – “baseball bat” retrieved March 5, 2011 from http://dee-wnax.itmblog.com/2009/08/Number 12 – “piece of paper” retrieved March 5, 2011 from http://www.curling.org.au/blog/Lists/Posts/Post.aspx?List=677e8176%2D8663%2D4361%2Da012%2D566d1db4b5a7&ID=31Number 13 – Microsoft 2007 Clipart, retrieved from document clipart “paper plane”, March 5, 2011Number 14 – Microsoft 2007 Clipart, retrieved from document clipart “corn”, March 5, 2011Number 15 – Microsoft 2007 Clipart, retrieved from document clipart “popcorn”, March 5, 2011Number 16 – “big car” retrieved March 5, 2011 from http://www.city-data.com/forum/automotive/139197-news-do-you-own-small-car.htmlNumber 17 – “rusty car” retrieved March 5, 2011 from http://www.bumpworthy.com/bumps/668Number 18 – Microsoft 2007 Clipart, retrieved from document clipart “firework”, March 5, 2011 Number 19 – Microsoft 2007 Clipart, retrieved from document clipart “firework”, March 5, 2011 Number 18 – Microsoft 2007 Clipart, retrieved from document clipart “confused”, March 5 2011Number 19 – Microsoft 2007 Clipart, retrieved from document clipart “glass bottle“, March 5, 2011Number 20 – Microsoft 2007 Clipart, retrieved from document clipart “recycled“, March 5, 2011Number 21 – Microsoft 2007 Clipart, retrieved from document clipart “aluminium can“, March 5, 2011Number 22 – Microsoft 2007 Clipart, retrieved from document clipart “plastic bottle“, March 5, 2011