chemistrya . Which element has the following electron configuration? (a) [He]2s1
ID: 907636 • Letter: C
Question
chemistrya
. Which element has the following electron configuration?
(a) [He]2s1 _____________
(b) [Ne]3s23p3_____________
(c) [Ar] 4s23d104p6 _______________
(d) [He]2s22p3 _____________
(e) [Ar]4s13d10______________
(f) [Ar]4s13d5_______________
Write the number of core and valence electrons in Ca and Mg.
Ca has ______ core electrons and ______ valence electrons.
Mg has _______core electron and ______ valence electrons.
Identify the element.
(a) The element that contains 10 core electrons and 5 valence electrons. ____
(b) Its (1+) ion contains 18 core electrons and 7 valence electrons. _____
Rearrange the following atoms/ions in decreasing order of radius:
(a) Cl, Mg, Ca, Ba : _________________________
(b) Al3+, Mg2+, Ca2+, F, O2 : ________________________
(c) Pb, Sn , Si, As: _________________________
5.
(a) [Ne] (b) [Ar]
Write down the set of isoelectronic ions (4 each) that have the same ion configuration as the noble gas.
_____,______,______, _____,______,______,
6. Arrange the 2nd period atoms in decreasing order of first ionization energy.
(Li, Be, B, C, N, O, F, Ar)
7. Arrange the 2nd period atoms in increasing order of electron affinity.
(Li, Be, B, C, N, O, F, Ar)
8. Write the condensed electron configuration for the following ion:
(a) Zn2+ _______________ (c) Co2+_______________ (e) Mn3+_______________
(b) Se2- _____________________ (d) Ti+ ____________________
(f) Sn2+ ____________________
9. True or false.
(a) Effective nuclear charge decreases going down a group. __________
(b) Zeff for calcium is smaller than that of chlorine. __________
(c) Al3+ is larger than Na+ because Na+ has two extra electrons. __________
(d) Effective nuclear charge (Zeff) is the positive charge experienced by the electron from the nucleus and it increases from left to right across the period. __________
(e) Anions are larger than their parent atoms because electrons are added to the valence shell reducing the electron-electron repulsions. __________
(f) The ionization energy of Na2+ is significantly higher than Na+ because it takes more energy to remove the inner-shell electron. __________
(g) Atomic radius tends to decrease from top to bottom of a group because of the increase in the principle quantum number. __________
(h) Bromine, calcium and sodium are metallic elements because they are on the left side of the periodic table. __________
(i) Calcium, antimony, and silicon are metalloids that their properties fall between those of metals and those of nonmetals. __________
10. Rearrange the following compounds in order of increasing acidity. (The more non-metallic the central atom, the more acidic the oxide is.) 2points
CO2, P2O5, CaO, SO3, SiO2, CO2
11. Consider the elements B, Ca, Cl, O, and S. (1 point each, Total 2 points)
(a) Identify the element that is most likely to form an ionic bond with magnesium. __________ (b) Identify the element that is most likely to form a covalent bond with nitrogen __________
12. Use orbital diagram to illustrate what happens when an oxygen atom gains two electrons.
Condensed electron configuration Orbital diagram
Explanation / Answer
Too many questions in one single post. Try to post one question at a time so you can get a better and faster answer for eachr of your question. In this ocassion, I'll answer the first 3 questions. The rest of your questions, post it per separate in differents questions posting.
1. a) [He] 2s1 means that the atomic number of He is 2, + 1 electron, that would be 3. This element is Lithium (Li)
b) The neon has a Z=10 + 2 electrons in the s orbital and 3 more in the p, results in 15. This element is Phosphorous (P).
c) Ar has a Z=18, + 2 electrons, 10 and 6 more, results in 36. This element is Krypton (Kr).
d) 7 electrons in total, this element is Nitrogen (N).
e) 18 + 1 + 10 = 29. This element is copper (Cu)
f) 18+1+5 = 24. This element is Cr (Chromium).
2. The Valence electrons are those electrons used to bond with another element or compound. For example, Oxygen has 6 valence electrons. If you write the electronical configuration:
[O] = 1s2 2s2 2p4
The last level of energy, has the information of the valence electrons. The previous level gives us the core electrons. So, following this:
Ca has 2 valence electrons and 18 core electrons.
Mg has 2 valence electrons and 10 core electrons.
3. The element with 10 core electrons (first two level of energy) and 5 valence electrons, correspond to an atomic number of 15, this element is P.
the element with his ions, with an atomic number of 25 correspond to the Manganese Mn.
The rest of the questions, post it per separate.
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