Which of the following occurs because of unequal heating of the Earth's surface?

tides

gravity

Moon phases

winds

Which sources of energy are used by humans to produce electrical energy? (a) Plants, animals, and fossil fuels (b) Wind, water, and fossil fuels (c) Water, wood, and wind (d) Wind, water, and soil

Anthracite is a type of coal that is composed of carbon with small amounts of hydrogen, oxygen, nitrogen, and sulfur. The formula for a sample of anthracite is C 240 H 90 O 4 NS. Calculate the amount of carbon in 40.0 kg of the sample.

Balance the following reaction: AI2O3 + HCI → AICI3 + H2O

Americans eat too much salt (NaCl). A healthy adult should eat no more than 6 g of salt in one day. Use this information to answer the following questions. (Round atomic masses to the nearest tenth unit.) a. What is the molar mass of NaCl? b.

Classify each of the following as an element or a compound: HCI, CO2, Cl, Li, and H20

Consider HA2, the intermediate form of a diprotic acid. Ka for this species is 1024 and Kb is 1028. Nonetheless, the Ka and Kb reac - tions proceed to nearly the same extent when NaHA is dissolved in water. Explain.

Which of the following is true of group 6A? Includes Chlorine Includes Sulfur Gain 2 electrons Tend to form + 2 ions Have 5 valence electrons

What happens if you pour water in baking soda? Does it release energy? What kind?

Define chemistry in relation to biology and physics

If you have 39 g of sodium azide in an air bag [2nan3 (s) - > 2na (s) + 2n2 (g) ], then how many molecules of nitrogen gas will it make at stp?