Answer:
Magnesium and calcium belong to the second group i. e. alkaline earth metals. They are known as earth metals because they are extracted from the earth. They are very reactive elements. Their reactivity increases when we go from top to bottom because the outermost electrons goes farther from the nucleus i. e. atomic radius increases so less energy is needed for its removal.
Speed is actually instantaneous speed, the speed an object is moving at that very instant.
But average speed is the total distance traveled divided by the total time.
Let's say you travelled 10 miles in 2 hours, your average speed would be 10 divided by 2, which is 10 miles / hr.
But during those 10 miles you may be accelerating, decelerating and be travelling 1 mile/hour and 20 miles/hour at another point. But your average speed would be total distance / total time. So your instantaneous speed can change throughout that period of time.
Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere. Power plants release the majority of sulfur dioxide and much of the nitrogen oxides when they burn fossil fuels, such as coal, to produce electricity. In addition, theexhaust<span> from cars, trucks, and buses releases nitrogen oxides and sulfur dioxide into the air. These pollutants cause acid rain.</span>
Very little electric force is required to cause electron flow in conductors. This is due to electrons called "free electrons", which exist in the atoms of conductors. "Free electrons" are electrons that are very weakly bonded to the atom. ... Metals such as copper, silver, and gold are good conductors.
Well, atoms are loosely bound and free to move through the material. Almost all, or just most, atoms will hold on to electrons very tightly and are insulators.
Answer:
because the electron is a negatively charge and have high energy
