Which elements have only one electron orbit or shell? A. hydrogen (H) and helium (He) B. helium (He) and lithium (Li) C. krypton (Kr) and iron (Fe) D. hydrogen (H) and calcium (Ca)

Following a volcanic eruption, which event is usually the last one to be observed

In which of these situations would light slow down? A. from plastic to air B. from ice to water C. from a vacuum to air D. from glass to air

Which compound plays an important role in leather processing and electroplating? nitric acid hydrochloric acid ammonia magnesium hydroxide

The chemical formula for the compound vanadium (V) oxide, which contains V5 + and O2 - ions, is

What is the difference between a strong electrolyte and a weak electrolyte

What does LeChatelier's principal mean

How many milliliters of a 0.7% stock solution are required to make 2 l of 0.2% solution? how many ml of solvent will be required to carry out the dilution?

What percentage of the naphthalene molecules emitted a photon?

In an endothermic reaction, heat is absorbed from the surroundings. How does this affect entropy? A. The particles in the surroundings move slower and have decreased entropy. B.

The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change that must happen at the molecular level? A. The molecules move more quickly and their average kinetic energy increases. B.