How many gold atoms are in a 0.490 ounce, 18 K gold bracelet? (18 K gold is 75% gold by mass.). Express your answer using two significant figures.
How many gold atoms are in a 0.490 ounce, 18 K gold bracelet? (18 K gold...
There is a 10.0 grams necklace made of 18K gold. K, karat, is a measurement of the fineness (or purity) of gold by Jeweler and gold dealers. Compared with 24K (pure gold), 18K means that the mass percent of gold is = 0.75 (or 75 wt%, we treat it as an exact number here). In another word, that necklace contain 75% gold by mass. If the international gold price today is $1323 (US) per troy ounce, and one troy ounce...
How many atoms are in each elemental sample? Part A.) 3.8 mol Cu Express your answer using two significant figures. Part B.) 5.1×10−3 mol C Express your answer using two significant figures. Part C.) 16.1 mol Hg Express your answer using three significant figures. Part D) 0.235 mol Na Express your answer using three significant figures.
Part A How many half-lives must elapse until 88 % of a radioactive sample of atoms has decayed? Express your answer using two significant figures 10 AED – O @ ? Submit Request Answer Part B How many half-lives must elapse until 97 % of a radioactive sample of atoms has decayed? Express your answer using two significant figures. IVO AXP = 0e? 1/2 Submit Request Answer Provide Feedback
How long will it take for 18 %% of the U−238U−238 atoms in a sample of U−238U−238 to decay? Express your answer using two significant figures.
Part A How many carbon atoms are there in a 1.3-carat diamond? Diamonds are a form of pure carbon. (1 carat = 0.20 grams) Express your answer to two significant figures. carbon atoms = Part B Calculate the mass of 2.25
44. How many atoms of gold are there in a pure gold ring with a mass of 10.6 g?
A sample of the male sex hormone testosterone, C19H28O2, contains 3.98×1021 atoms of hydrogen. How many atoms of carbon does it contain? Express your answer in atoms to three significant figures. How many molecules of testosterone does it contain? Express your answer in molecules to three significant figures.
How many atoms are there in 2.30 g Hg? Express your answer using appropriate units and significant figures.
Exercise 6.17 Part A How many mercury atoms are in 6.1 mol of mercury? Express your answer using two significant figures. Hg atoms Submit Provide Feedback O FA FS F6 esc Fl F2 F3 1%
Part C If a room contains 25000 atoms of radon-222, how many atoms of radon-222 remain after 15.2 d? Express your an Swer using two significant figures. IVO ADO ? atoms of radon-222 Pearson