Question

1. when looking at a density column, the most dense substance will be located...

a. at the top
b. near the top
c. in the middle
d. at the bottom
e. need more information

1. the valence shell of the alkali metals has...

a. 1 electron in the s orbital
b. 2 electrons in the s orbital
c. 1 electron in the p orbital
d. 2 electrons in the p orbital

1. what is 1.6 x 10⁻⁴ in standard form?

a. 1600
b. 1.60000
c. 0.00016
d. 0.16 x 10⁻⁵
e. 0.016 x 10⁻⁶

1. ionic bonds happen between...

a. metal and metal.
b. metal and nonmetal.
c. nonmetal and nonmetal.
d. none of the above.

1. what is the formula for the compound formed by zinc ions, zn⁺², and fluoride ions, f⁻¹?

a. znf
b. zn₂f
c. znf₂
d. zn₂f₃

1. each arrow shows an electron moving from one energy level to another. which transitions will release energy?

electron transitions in h - atom diagram
a. a and d
b. b and c
c. only a
d. only c

1. going down a group of elements, the atomic radius...

a. increases.
b. remains approximately constant.
c. decreases regularly.
d. decrease, but not regularly.

Explanation:

1. For question 48: Denser substances sink below less dense materials in a density column, so the most dense is at the bottom.
2. For question 49: Alkali metals are Group 1 elements, they have one valence electron in the s orbital.
3. For question 50: $10^{-4}$ shifts the decimal 4 places left, so $1.6\times10^{-4}=0.00016$.
4. For question 51: Ionic bonds form when metals transfer electrons to nonmetals creating charged ions that attract.
5. For question 52: Balance charges: $Zn^{+2}$ needs two $F^{-1}$ ions to form a neutral compound.
6. For question 53: Electrons release energy when moving from a higher energy level to a lower one, transitions A and D do this.
7. For question 54: Atomic radius increases down a group as new electron shells are added.

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Answer:

1. d. at the bottom
2. a. 1 electron in the s orbital
3. c. 0.00016
4. b. metal and nonmetal.
5. c. $\boldsymbol{ZnF_2}$
6. a. A and D
7. a. increases.