[tortoise]

Which of the following are chemical properties, and which
are physical properties?
And my answers are next to the questions.

1/
(a) Baking powder gives off bubbles of  carbon  dioxide when  added  to water.  --- Chemical
(b) A  particular type of steel consists of 95% iron, 4% carbon, and 1% mis-cellaneous other elements. --- Physical
(c) The density of gold  is 19.3 g/mL.  --- Physical
(d)  Iron  dissolves  in  hydrochloric  acid  with  the evolution of hydrogen gas. --- Chemical
(e) Fine steel wool burns in air. --- Chemical
(f ) Refrigeration slows the rate at which fruit ripens. --- Chemical

2/
(a) Metallic sodium is soft enough to be cut with a knife. --- Physical
(b) When sodium metal  is cut, the surface  is  at  first  shiny; after  a  few  seconds  of  exposure to  air,  it  turns  a  dull  gray. --- Physical
(c) The  density  of  sodium  is 0.97  g/mL.  --- Physical
(d)  Cork  floats  on  water. --- Physical
(e) When  sodium comes in contact with water, it melts, evolves a flammable gas,  and  eventually  disappears  altogether.  --- Chemical
(f ) Household bleach changes the color of your favorite T-shirt from purple to pink. --- Chemical

How many of my answer are right?  

[Borek]

2b - think again. What happens?

[tortoise]

What happens next? You mean the following reaction would happen?

Na + H₂0 = NaOH + 1/2H₂

Right?