Liquid petrol does not ignite spontaneously when exposed to the air because there is not enough molecules that contains energy to reach the activation energy. As a result, the reaction cannot proceed and a supply of energy should be added for the reaction to occur.
<em>Answer:</em>
<em>B.) A hot liquid or air that expands, becomes less dense, and rises or becomes more dense and sinks.</em>
<em>Explanation:</em>
<em>Convention is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.</em>
Answer:
Hey
of course, the damage of a collision depends upon how fast to objects are moving at each other and how strong they are. If you have two tanks moving at each other 2 miles per hour it will be very little damage and the ->shape<- will not change much, maybe a dint or two. But if two balloons filled with water are moving at each other 5000 mph they will completely evoporate in a burst of light, and their ->shape<- will change very much. This is how shape and motion are related.
Hope it helped
spiky bob your answerer
<span>C. Gravity acts on all objects in the universe.
think about Newtons Laws of Motion</span>
