With reference to He-4, explain the term isotopes.

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?