Help with some baby chem problems!

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<p>I know this might not be the right section to put it but, this thread should be active and i just need clarification on a few college intro chem questions:</p>

<p>A breif explaination would be really nice too. ill also put what i make of the problem.</p>

<p>1) For which of these group IA metals is the shielding effect by the core electrons expected to be the strongest?</p>

<p>A) Fr
B) Rb
C) Na
D) H</p>

<p>Im not too sure what this question means, but i know the strongest metal is Fr right?</p>

<p>2) The maximum number of electrons that can be held in one 5d orbital is?</p>

<p>A) 10
B) 7
C) 5
D) 1
E) 2</p>

<p>This one i thought it was 10, since the D shells can hold 10 electrons, but then in one orbital..thats throwing me off because im thinking about the orbital diagram, and each box can hold 2 electrons.</p>

<p>3) Which of the following is true about spin pairing?</p>

<p>A) It brings about a small attraction between electrons in the same orbital
B) It contributes nothing to the electronic structure of atoms
C) It allows 3 electrons to reside in one atomic orbital
D) It completely overcomes the electrostatic repulsion between 2 electrons in the same orbital.</p>

<p>i have it narrowed between A and D.</p>

<p>4) Elements with valence electrons in the 2nd energy level are all in the
Same period or Same group?</p>

<p>i was leaning towards period but not sure because i got confused with what the second energy level is.</p>

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<p>Shouldn't #4 be groups (vertical)?
I'm not a chemistry junkie, but I'm pretty confident about my answer.</p>

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<ol>
<li><p>A - shielding effect is caused by electrons in lower energy levels "shielding" the electrons at the outer most level (valance electrons). Since Fr has most energy levels among the choices, it has the highest shielding effect. this makes its atomic radius relatively large as well.</p></li>
<li><p>E, i think. this one is just about terminology. the 5d subshell can hold 10 e-'s, but each orbital can hold only two, spin up and spin down.</p></li>
<li><p>i dunno but it might be A because the "small attractions" might be the forces that account for orbital shapes.</p></li>
<li><p>period. 2nd energy level is just anything that ends with 2p</p></li>
</ol>

<p>hope these are right and hope it helps.</p>

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<p>Thanks dococtopi, 1 and 4 are right. Im hesistant to put in answers for 2 and 3, so ill probably associate with other classmates first.</p>

<p>also this is the last question im unsure about because the terminology is getting to me, or atleast an explaination.</p>

<p>group A elements fill what orbitals?</p>

<p>a) s only
b) d only
c) s and p
d) d and f</p>

<p>after reading what a few classamtes posted on our class discussion board, many of them said its not s or s and p (not a or c). so i didnt understand, dont group A elements, alkali and alkaline earth metals, up s and p's?</p>

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<ol>
<li><p>A. There are more electrons "covering" the nucleus on the biggest element, which is Fr</p></li>
<li><p>C. The electrons space out until "forced" to form multiple orbitals by pairing up. So, since there are 5 orbitals in the d subshell, you can put one electron into each one before having to pair up and create more than one orbital...at least, this is what I think is the answer</p></li>
<li><p>D. A is false because the electrons never attract each other, and prefer not to be in the same orbital unless forced to. So it only overcomes the repulsion</p></li>
<li><p>Period, the second energy level is the second row of elements on the table. (2s2p) </p></li>
</ol>

<p>Your last question: C, they take up s and p orbitals.</p>

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<p>Number 2 is definitely not C.</p>

<p>Depending on how you interpret the question, it can be either A or E like doctopi said; the d-subshell has 5 orbitals capable of holding a total of 10 electrons. Each individual orbital in the d-subshell can hold 2 electrons.</p>

<p>Other than that, the rest of lolcats4's answers seem to be right. For question 4, keep in mind that 2d is also an option, not just 2s or 2p (ie, the transition metals/d block).</p>

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<ol>
<li><p>Everyone has answered you already.</p></li>
<li><p>(E) A subshell is 1s, 2s, 2p, 3s, 3p. An orbital can fit 2 electrons, it is like 2px, 2py, 3px, 3d(x2-y2) etc. </p></li>
<li><p>I'm disagreeable to (D) because no matter what, for two negatively-charged particles, there'll always be some repulsion between them. Still, (A) doesn't seem perfect to me. Check out this website? </p></li>
</ol>

<p>Ask</a> Me A Chemistry Question: Why do electrons pair when they repell each other?</p>

<ol>
<li><p>Everyone has answered you already.</p></li>
<li><p>Group A are main block elements, i.e. excluding transition metals. So it's S & p.</p></li>
</ol>

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<p>Yeah, fiona brings up a good point on #3. Some of these are pretty bad questions.</p>

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<p>I don't like my answer to 2 either, but since the OP was hesitant to put in the answer I thought there was some trick. My first impulse was A. </p>

<p>And 3 is a terrible question, I agree.</p>

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<p>THanks to everyone for there help! if you guys are interested in the answers
here they are! :</p>

<p>1) A
2) E
*3) A
4) Period</p>

<p>I posted a 5th one after about orbitals
5) B - Answer: D Only</p>

<p>*3 is because everyone was discussing it, its actually A.</p>

<p>To Gold shadow or anyone else:</p>

<p>Since when is there a "2d"?</p>

<p>I thought the D shells start at 3?
Period 4 of s = n, d = (n-1), d = 3...</p>

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<p>Oh wow, you're right. I'm not sure how that completely slipped my mind. Yeah, d starts at 3, my bad.</p>

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<p>yeah #2 is a tricky question..they throw in the 5d to try and trick you. As the case in any orbital, it has 5 orbitals that hold 2 electrons EACH</p>

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<p>are those questions from the SAT II Chemistry test/review?</p>