Which 2 elements have the same number of valence electrons? Group of answer choices

magnesium & sodium

sodium & potassium

hydrogen & helium

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.

Which of the following accurately describes the correct order of events in the process of transpiration within a plant? a. water enters the roots, passes through the leaves, and leaks through the stem pores. b. water enters the roots, gets transported through the stem, and evaporates through the leaves. c. water is absorbed through the leaves, is transported through the stem, and nourishes the roots. d. water is absorbed through the leaves, nourishes the roots, and leaks through the stem pores.

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?