The answer is A for number 1 and D for 2
Answer:
The answer to your question is below
Explanation:
When we have the number of an element followed by a number, that number is the atomic mass.
Atomic mass is the number of protons plus neutrons.
Protons Neutrons
Carbon-13 6 13 - 6 = 7
Chromium-51 24 51- 24 = 27
Strontium-88 38 88 - 38 = 50
Boron-10 5 10 - 5 = 5
Answer:
storm runoff
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The answer is 492.8 g
1. Calculate a number of moles of a sample.
2. Calculate a molar mass of C3H8.
3. Calculate a mass of the sample.
1. Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance: 6.023 × 10²³ units per 1 mole
6.023 × 10²³ atoms : 1 mol =6.72 × 10²⁴ atoms : n
n = 6.72 × 10²⁴ atoms * 1 mol : 6.023 × 10²³ atoms = 1.12 × 10 mol = 11.2 mol
2. Molar mass (Mr) of C3H8 is sum of atomic masses (Ar) of its elements:
Ar(C) = 12 g/mol
Ar(H) = 1 g/mol
Mr(C3H8) = 3 * Ar(C) + 8 * Ar(H) = 3 * 12 + 8 * 1 = 36 + 8 = 44 g/mol
3. Mass (m) of a sample is number of moles (n) multiplied by molar mass (Mr) of C3H8:
m = n * Mr = 11.2 mol * 44 g/mol = 492.8 g
Answer:
5.17 × 10^-1
Explanation:
move the decimal to the right one space.
when you move the decimal to the right its exponent becomes a negative.
