In manipulative studies, it is necessary to have an experimental group and a group.

control group

Explanation:

In manipulative studies, it is necessary to have an experimental group and a control group.

correct answer: false

while planning water activities, it is very important to consider the weather, because if we do not plan and are going for a surf, then it might be that the hurricane came and drown us or may carry us to long distance from where we can not come back. there are many reasons to take information about the weather when we are planning any water activities.

hence, the correct answer would be false.

oxygen is the first element in group 16 (via) of the periodic table. the periodic table is a chart that shows how chemical elements are related to each other. the elements in group 16 are said to belong to the chalcogen family. other elements in this group include  sulfur, selenium, tellurium,  and  polonium.  the name chalcogen comes from the greek word  chalkos,  meaning "ore." the first two members of the family, oxygen and sulfur, are found in most ores.

oxygen is by far the most abundant element in the earth's crust. nearly half of all the atoms in the earth are oxygen atoms. oxygen also makes up about one-fifth of the earth's atmosphere. nearly 90 percent of the weight of the oceans is due to oxygen. in addition, oxygen is thought to be the third most abundant element in the universe and in the solar system.