Answer: The bold staircase in the periodic table allows us to classify which elements are metalloids.
Explanation: Additionally, it acts like a "divider" that allows us to properly distinguish the metals from the non-metals in the periodic table.
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Your answer is going to be b
Answer:
29,200 cal = 1.22 E 5 joules
Explanation:
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Answer:
0.0468 g.
Explanation:
- The decay of radioactive elements obeys first-order kinetics.
- For a first-order reaction: k = ln2/(t1/2) = 0.693/(t1/2).
Where, k is the rate constant of the reaction.
t1/2 is the half-life time of the reaction (t1/2 = 1620 years).
∴ k = ln2/(t1/2) = 0.693/(1620 years) = 4.28 x 10⁻⁴ year⁻¹.
- For first-order reaction: <em>kt = lna/(a-x).</em>
where, k is the rate constant of the reaction (k = 4.28 x 10⁻⁴ year⁻¹).
t is the time of the reaction (t = t1/2 x 8 = 1620 years x 8 = 12960 year).
a is the initial concentration (a = 12.0 g).
(a-x) is the remaining concentration.
∴ kt = lna/(a-x)
(4.28 x 10⁻⁴ year⁻¹)(12960 year) = ln(12)/(a-x).
5.54688 = ln(12)/(a-x).
Taking e for the both sides:
256.34 = (12)/(a-x).
<em>∴ (a-x) = 12/256.34 = 0.0468 g.</em>
Answer:
1.20atm
Explanation:
Given parameters:
Partial pressure of gas 1 = 0.35atm
Partial pressure of gas 2 = 0.20atm
Partial pressure of gas 3 = 0.65atm
Unknown:
Total pressure of the gas mixture = ?
Solution:
To solve this problem, we need to recall and understand the Dalton's law of partial pressure.
Dalton's law of partial pressure states that "the total pressure of a mixture of gases is equal to the sum of the partial pressure of the constituent gases".
Total pressure =Pressure of gas(1 + 2 + 3)
The partial pressure is the pressure a gas would exert if it alone occupied the volume of the gas mixture.
Now we substitute;
Total pressure = (0.35 + 0.20 + 0.65)atm = 1.20atm
