Review | Constants | Periodic Table In 1999, scientists discovered a new class of black holes with masses 100 to 10,000 times the mass of our sun that occupy less space than our moon. Suppose that one of these black holes has a mass of 1 x 104 suns and a radius equal to one-half the radius of our moon. ▾ Part A What is the density of the black hole in g/cm³? The radius of our sun is 7.0 x 105 km, and it has an average density of 1.4 × 103 kg/m³. The diameter of the moon is 2.16 x 103 miles. 1 km = 0.6214 mile Express your answer in grams per cubic centimeter to two significant figures. ΜΕ ΑΣΦ Density of the black hole = 3.502 1013 Submit Previous Answers Request Answer × Incorrect; Try Again; One attempt remaining Provide Feedback Search ? g/cm³ Next > 9:33 AM 9/5/2024

A 124-g sample of a pure liquid, liquid A, with a density of 3.00 g/mL is mixed with a 40.8-mL sample of a pure liquid, liquid B, with a density of 2.00 g/mL. What is the total volume of the mixture? (Assume there is no reaction upon the mixing of A and B, and volumes are additive.)

The mole is the SI unit for the amount of a substance. The mass of one mole of pure table sugar is 342.3 grams. How many grams of sugar are in exactly 1/2 mole? What is the mass of 0.764 mole?

Which of the following represent physical properties or changes, and which represent chemical properties or changes? You curl your hair with a curling iron. You curl your hair by getting a “permanent wave” at the hair salon. Ice on your sidewalk melts when you put salt on it. A glass of water evaporates overnight when it is left on the bedside table. Your steak chars if the skillet is too hot. Alcohol feels cool when it is spilled on the skin. Alcohol ignites when a flame is brought near it. Baking powder causes biscuits to rise.

A sphere of pure iron metal contains 9.57 X 10^24 Fe atoms. What is the radius of the sphere in centimeters? (The density of Fe is 7.874 g/cm^3)

An aluminum cylinder is 0.512 ft in length and has a diameter of 0.3142 inch. The density of aluminum is 2.70 g / cc. MW of aluminum is 26.981538. What is the volume of the aluminum cylinder in cm3? What is the mass of the aluminum cylinder in g? Calculate the number of aluminum atoms present in the cylinder?

Combining one atom of carbon with two atoms of oxygen produces one molecule of carbon dioxide, along with 6.5 x 10-19 J of energy. In 2019, the United States burned enough coal to supply 1.1 x 1019 J of energy. Assuming that coal is roughly 100% carbon, how many molecules of carbon dioxide did the U.S. produce by burning coal in 2019? Less than 1036 molecules of carbon dioxide. Between 1036 and 1038 molecules of carbon dioxide. Between 1038 and 1040 molecules of carbon dioxide. More than 1040 molecules of carbon dioxide.

Mr. Auric Goldfinger, criminal mastermind, intends to smuggle several tons of gold across international borders by disguising it as lumps of iron ore. He commands his engineer minions to form the gold into little spheres with a diameter of exactly 8 cm and paint them black. However, his chief engineer points out that customs officials will surely notice the unusual weight of the "iron ore" if the balls are made of solid gold (density 19.3 g/cm"). He suggests forming the gold into hollow balls One of the balls of fake instead (see sketch at right), so that the fake "iron ore" has the same density as real iron ore (5.15 g/cm'). "iron ore," sliced in half. Calculate the required thickness of the walls of each hollow lump of "iron ore." Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

1) Combination Reactions (A+ B à AB): Two elements (or simple compounds) become one compound. Mg(s) + O,(g) à MgO(s) SO((g) S(s) + O2(g) à 2) Decomposition Reactions (AB à A+ B or ABC à AC + BC): A compound becomes two or more elements (or simpler compounds). Н,О() а Н,(g) + 0,(g) CO,(g) CUCO;(s) à CuO(s) + 3) Single Replacement Reactions (A+ BC à AC + B): An element (a metal or a halogen) replaces another element (metal or halogen) in solution. Zn(s) + CUSO,(aq) à ZnSO̟(aq) + Cu(s) NaBr(aq) à NaClI(aq) + Br,(aq) Cl,(aq) + 4) Double Replacement Reactions (AB + CD à AD + CB): Two elements "switch" (metals replace each other or hydrogen and a metal replace each other). Nal(aq) + Pb(NO,),(aq) à NaNO,(aq) à PbI,(s) NaOH(aq) ӑ H,О() + NaCl{aq) НС(аq) + Reactions may be done in any order. You DO NOT have to indicate the phase(s) of the products. Record observation(s) and write the balanced chemical equation in Table 1. Reaction #1 has been done for you. 1. Using a test tube and dropper…

What is the mass of  1.42x10^24 atoms of oxygen?  grams What is the mass of 5.01x10^23 molecules of oxygen?