How is firelight produced

Who discovered citrine?

Which is the electron configuration for lithium? 1s2 2s3

Carbon disulfide, CS2, can be made from coke, C (s), and sulfur dioxide, SO2 (g). C (s) + SO2 (g) à CS2 (s) + CO2 (g) If the actual yield of CS2 is 86.0% of the theoretical yield, what mass of coke is needed to produce 950. grams of CS2?

Sulfurous Acid, H2SO3, is a diprotic acid, with the following acid dissociation constants: Ka1 = 1.4 * 10-2 Ka2 = 6.7 * 10-8 What is the Kb for SO32 - at 25ºC? Group of answer choices 9.4 * 10-10 1.5 * 10-7 6.7 * 10-8 7.2 * 10-13

The atomic masses of 79Br35 (50.69 percent) and 81Br35 (49.31 percent) are 78.9183361 and 80.916289 amu, respectively. Calculate the average atomic mass of bromine. The percentages in parentheses denote the relative abundances.

7 An atom that has 13 protons and 15 neutrons is an isotope of the element (1) nickel (3) aluminum (2) silicon (4) phosphorus

The graph below shows how solubility changes with temperature. What is the solubility of Na2HAsO4 at 60°C? 20 g/100 mL of water 46 g/100 mL of water 65 g/100 mL of water 70 g/100 mL of water

Which statement regarding water is true? Energy must be given off in order to break down the crystal lattice of ice to a liquid. Hydrogen bonds are stronger than covalent bonds. Liquid water is less dense than solid water.

Which of the following elements has the fewest valence electrons?. a. beryllium. b. boron. c. carbon. d. lithium

How many molecules are in 4.50 moles of H2O? A. 450 molecules B. 6.02 x 1023 molecules C. 2.71 x 1024 molecules D. 3.00 molecules