For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
Explanation:
Here's an oxidation chart to help
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B. Because there are 3 molecules in right and 2 molecules in the left, so entropy rises.
Answer:
C. 17 grams.
Explanation:
∵ mass % = [mass of solute/mass of solution] x 100.
mass of solute (NaCl) = ??? g & mass of solution = 140.0 g.
<em>∴ mass of NaCl = (mass %)(mass of solution)/100 </em>= (12.0)(140.0)/100 = <em>16.80 g ≅ 17.0 g.</em>
Answer:
32, 30 and 41
Explanation:
The problem here is to find the number of:
Protons, neutrons and electrons in Ge²⁺
In this ion,
We must understand that for a net positive charge to remain on an atom, the number of protons must be greater than the number of electrons.
Ge is Germanium with atomic number of 32;
So the number of protons is 32
Since the atom has lost two electrons;
Number of electrons now is 32 - 2 = 30
Number of neutrons is 41 from the periodic table.
