Question

2
multiple choice 1 point
using the periodic table, what is the predicted last
orbital notation for actinium (ac)?
4f7
5f1
6d1
7s2
3
formula 1 point
a gas with a volume of 9.4l at a pressure of
251.9kpa is allowed to expand to a volume of
41.6l. what is the pressure in the container in
kpa if the temperature remains constant? round
to 1 decimal place.
answer

Explanation:

Problem 2

Actinium (Ac) is in period 7 and group 3. The electron - filling order for elements in the actinide series (which Ac starts) has the last electron in the \(6d\) orbital. For example, the electron configuration of Ac is \([Rn]7s^{2}6d^{1}\), so the last orbital notation is \(6d^{1}\).

Step1: Identify the formula

Since the temperature is constant, we use Boyle's law \(P_1V_1 = P_2V_2\).

Step2: Rearrange the formula for \(P_2\)

\(P_2=\frac{P_1V_1}{V_2}\)

Step3: Substitute the values

Given \(P_1 = 251.9\space kPa\), \(V_1=9.4\space L\), and \(V_2 = 41.6\space L\)
\(P_2=\frac{251.9\times9.4}{41.6}\)

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Answer:

C. \(6d^{1}\)

Problem 3