• http://www.youtube.com/watch?v=Xi3oI_mGOHQ&feature=related

• Gymnastics

So the link…

• What do weight lifting, gymnastics and Chemistry have in common?

Chemistry of chalk and MgCO3,

The lifters use chalk on their hands to aid gripping the bar and to remove moisture, which could cause the bar to slip.

Weightlifting and the link to chemistry

Chalk, a naturally occurring or man-made substance, is engulfed with chemistry and it is here that a link between chemistry and weightlifting can be found.

Lawn tennis – line boundaries of courtWhen the ball hits a boundary line it makes a cloud of dust. Natural chalk has mostly been replaced with titanium oxide now in tennis.

Gymnastics & rock climbing – stop slipping• Chalk is applied to hands, arms & legs to stop

slipping and absorb moisture.• Natural chalk has mostly been replaced with magnesium carbonate here.

Chalk in sport

Small amount found in tooth paste

Implements to write with on black boards or for pavement drawings

Other uses of chalk

Chalk is:

Natural chalk is formed in the ground and is:• Porous sedimentary rock – can hold water• A form of limestone• Composed of the mineral calcite

• A soft solid• White• It can also be found naturally as red in colour

The characteristics of chalk

It has similar characteristics to chalk in that it is a white, soft solid.

Natural chalk has widely been replaced with a man-made chalk called magnesium carbonate.

Draw a dot and cross diagram and describe the bonding. What are the properties?

The empirical formula of magnesium carbonate is MgCO3.

Man-made chalk

Magnesium carbonate, although used in sport, also has a range of other uses which include being used in:

• Flooring• Fireproofing• Fire extinguishing• Cosmetics• Dusting powder• Drying agents• Laxatives for loosening bowels