According to Dalton, what happens to atoms during a chemical reaction? Atoms gain or lose energy. Atoms are rearranged. Old atoms are destroyed. New atoms are created.

Which of these layers inside Earth is the hottest? A. Crust B. outer Core C. Lower mantle D. Asthenosphere

How many moles of water are produced when 3.0 moles of hydrogen gas react with 1.8 moles of oxygen gas? Balanced equation: 2H2 + O2 → 2H2O 3.0 moles of water 3.6 moles of water 5.3 moles of water 7.0 moles of water

If white light falls on a piece of white paper in a dark room, the paper appears white to the eye. This is because the paper reflects all the colors of light that fall on it.

Which formula represents a polar molecule? (1) O2 (2) CO2 (3) NH3 (4) CH4

Combining 0.320 mol Fe2O3 with excess carbon produced 10.8 g Fe. Fe 2 O 3 + 3 C ⟶ 2 Fe + 3 CO a. What is the actual yield of iron in moles? b. What is the theoretical yield of iron in moles? c. What is the percent yield?

Phosphorus trichloride, PCl₃ is a liquid at room temperature. Explain this observation in terms of the particles, structure and bonding of PCl₃.

4. Thorium-234 has a half-life of 24.1 days. What percentage of the original thorium-234 in a sample will remain after 144.6 days?

Which statement (s) is/are true of acid-catalyzed alcohol dehydrations? A) Protonation of the alcohol is a fast step. B) Formation of a carbocation from the protonated alcohol is a slow step.

Water is composed of hydrogen and oxygen, True Or False

Why must chromosomes be copied before cells divide