$m=m_{0}*(\frac{1}{2})^{\frac{60}{30}}\\\\
m=m_{0}*(\frac{1}{2})^{2}\\\\
m=\frac{1}{4}m_{0}$

If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>A. one-fourth</span>

7 0

2 years ago

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How many carbon atoms does the common group of amino acids have? a. 0 c. 2 b. 1 d. 3

zzz [600]

I definitly believe the answer is c. 2

4 0

3 years ago

Looking at the following equation, what coefficient should be placed in front of the H2? Fe + H2SO4 --> Fe2(SO4)3 + H2

Hatshy [7]

Answer:

3 (three)

Explanation:

2 Fe + 3H2SO4 = Fe2(SO4)3 + 3 H2 (basically just balance both sides)

6 0

2 years ago

Calculate the molar concentration of the Cl⁻ ions in 0.65 M CaCl2(aq), assuming that the dissolved substance dissociates complet

alexandr1967 [171]

The question here is solved using basic chemistry. CaCl2(aq) is an ionic compound which will have the releasing of 2 Cl⁻ ions ions in water for every molecule of CaCl2 that dissolves.
CaCl2(s) --> Ca+(aq) + 2 Cl⁻(aq)
[Cl⁻] = 0.65 mol CaCl2/1L × 2 mol Cl⁻ / 1 mol CaCl2 = 1.3 M
The answer to this question is [Cl⁻] = 1.3 M

5 0

3 years ago