4. You are asked to explain physical and chemical changes using a newspaper How will you demonstrate the two types of changes?
5. A brick is broken into several pieces. What type of change is involved? Will the mass and
volume change?

Infants born with severe respiratory problems are sometimes given liquid ventilation: they breathe a liquid that can dissolve more oxygen than air can hold. one of these liquids is a fluorinated compound, cf3(cf2)7br. the solubility of oxygen in this liquid is 66 mlo2 per 100 ml liquid. in contrast, air is 21 % oxygen by volume. calculate the moles of o2 present in an infant's lungs (volume: 12 ml ) if the infant takes a full breath of air. assume a pressure of 1 atm in the lungs.

How much energy is made when a pice of wood burns. how do you know

Which of the following units is not an official si unit? mole liter kilogram ampere