4. Which supports the presence of dark
energy?
A IThe universe formed in a big bang.
B Galaxies are moving away from us and
from each other.
C Galaxies that are farther away from us
are
moving away from us at a faster rate.
D The speed at which galaxies are moving
apart is accelerating.

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

Ase your answer to this question on the information below.hydrocarbons and fissionable nuclei are among the sources used for the production of energy in the united states. a chemical reaction produces much less energy than a nuclear reaction per mole of reactant.the balanced chemical equation below represents the reaction of one molecule of a hydrocarbon with two molecules of oxygen.chemical equation: ch4 + 2o2 → co2 + 2h2o + 1.48 × 10−18 jthe nuclear equation below represents one of the many possible reactions for one fissionable nucleus. in this equation, x represents a missing product.nuclear equation: write an isotopic notation for the missing product represented by x in the nuclear equation.

The alkali metals (group 1) consist of lithium (3), sodium (11), potassium (19), rubidium (37), cesium (55), and francium (87). they are soft, metallic solids with low densities and low melting points. based on the data shown in figure 1, how many valence electrons do alkali metals share?