How many unpaired valence electrons are there in a nitrogen atom? 95%
In-class activities A. B. C. D.
February 4, 2010 Afternoon class results
A. One. B. Two. C. Three. D. Five.
N
0% A.
N 12%
7%
A.
7%
B.
C.
D.
D.
D. there is no more room available in its outermost occupied shell.
88%
7% 0% A.
B.
5% C.
D.
Magnesium ions carry a 2+ charge, and chloride ions carry a 1– charge. What is the chemical formula for the ionic compound magnesium chloride? 1.
An atom loses an electron to another atom. Is this a physical or a chemical change for the atom that lost the electron?
A. Physical change involving the formation of negative ions. B. 1. Chemical change involving the 2.formation of negative ions. C.3. Physical change involving the formation of positive ions. 4. D. Chemical change involving the formation of positive ions.
C.
A. its nuclear charge is not great enough. B. that would result in a positive A. ion. C.B.of the repulsions they would have with electrons in the C. same shell. D.
74%
A. One. B. Two. C. Three. D. Five.
B.
0%
The neon atom tends NOT to gain any additional electrons because
How many bonds is nitrogen able to make?
A. B. C. D.
5%
71%
66%
2. 3.A. MgCl 4.B. Mg Cl 2
C. MgCl2 D. Mg2Cl2
19%
7%
7%
2% 1
20%
2
3
4
1
2
7%
3
4
1
What is the chemical formula for calcium chloride? 1. 2. 3. 4. 5.
Any of these could be it CaCl Ca2Cl CaCl2 Ca2Cl2
When nitrogen and fluorine combine to form a molecule, the most likely chemical formula is
63%
23% 13% 3%
0% 1
2
3
4
5
1. 2. A. N3F 3. B. N2F 4. C. NF4 D. NF answer text... 5. Enter
The formula can be determined by paying attention to the valence electrons: calcium has 2, that’s why it’s in group 2; and chlorine has 7, like all elements in group 17. Chlorine has a place for one more electron in it’s valence shell, and it collects this one from the calcium. But since calcium has two available, two chlorines take advantage of this. The resulting molecule has a net charge of zero: 2 chlorine bonded to 1 calcium.
74%
E. NF3 13% 3% 1
A hydrogen atom does not form more than one covalent bond, because it
1. A. has only one shell of electrons. 2. B.3. has only one electron to share.
79%
1
5
Cl with Cl 88%
C. ionic, ionic, covalent
2
Atoms of metallic elements can form ionic bonds, but they are not very good at forming covalent bonds. Why?
D. Their valence shells are already filled with electrons.
4
B. ionic, metallic, covalent
D. covalent, metallic, ionic
2%
C. They are on the wrong side of the periodic table.
3
Na with Cl Na with Na 1. 2. 3.A. metallic, covalent, covalent 4.
19%
1. E
2
Classify the following bond as ionic, covalent, or metallic (Na, atomic number 11; Cl, atomic number 17)
C. loses its valence electron so readily.
A. These atoms are too large to be able to 2. come in close contact with other atoms. 3. tendency to lose B. They have a great electrons. 4. nter answer text...
10%
0%
10% 2% 1
3
0% 2
3
4
How many electrons are used to draw the electron-dot structure for hydrogen peroxide, a covalent compound with the formula H2O2? 1. 2. 3. 4.
Enter answer text...
A. 14 B. 8 C. 7 D. 4
2
