Almost all properties are common to elements within a single group on the periodic table. They react with water in the same way, they have the same number of valence electrons thereby having the same valency, the number of shells in the atom of the element increases by one as we move down the group.
In general, they have the same chemical properties as chemical properties depend on the number of electrons in the valence shell i.e. the outermost shell in the atom of an element.
Answer:
hot air rises because gases expand as they heat up.When air heats up and expands,its density also increases.The warmer,less dense air effectively floats on top of the colder, dense air below it. This creates a buoyant force that causes warmer air to rise.
cold air sinks because it is heavier as its more dense ( because of closely packed molecules) soits harder for them to move and they absorb less energy. Also, gravity pulls on it more strongly.
Hope it helps :)
Answer: when the temperature is increased, the number of collisions per second increases.
Explanation:
the rate of collisions and the temperature is directly proportional. If the energy of the gas particles is boosted by using the temperature, the chances of the particles bumping into each other due to the high energy increases, thus increasing the number of collisions. This also increases the rate of reaction. Thus when temperature is increased the number of collisions also increases.