D. Not all mixtures are heterogeneous
• Before the balloon was placed inside the hot water, the pressure was the same inside and outside the balloon. The hot water raised the kinetic energy of the air molecules inside the balloon, expanding the balloon, through thermal expansion.
• (1) the pressure of air inside the balloon increased, (2) the volume of the inside of the balloon increased as well, and (3) the temperature of the balloon increased. Note that pressure and volume are inversely proportional, and pressure and temperature are directly proportional. Therefore as the temperature increases, the pressure inside will increase, causing an increase in the volume. At a certain point though the volume will increase too much as to cause a significant decrease in pressure.
• The air molecules will gain kinetic energy, hence (1) increasing the molecules's speed, and (2) heating the air molecules.
C.
This is because the water has undergone a physical change meaning that the effects can be reversed. If nothing was added or lost from the water the ice would be the exact same weight.
Oxygen is needed to carry out a lot of biochemical processes in the body. If the amount of oxygen available to the blood decreases significantly a lot of things will go wrong in the body. For instance, lack of adequate oxygen will lead to the death of neurons which will eventually leads to brain cells death and irreparable brain damage. Oxygen is also needed for cellular respiration, without respiration, there will not be oxygen for carrying out various cellular activities and this will result into death. Oxygen deprivation will also leads to difficulty in breathing and other associated problems.
