Question

unit 2 the atom test
part 1 multiple choice: select the letter choice that best answers the question and record on your answer sheet

1. a neutral atom may contain 8 protons,

a. 9 neutrons and 10 electrons.
b. 9 neutrons and 8 electrons.
c. 8 neutrons and 10 electrons.
d. 10 neutrons and 9 electrons.

1. you can determine the identity of an element if you know how many ____ it has.

a. protons b. neutrons c. electrons d. energy levels

1. the nucleus of an atom has all of the following characteristics except that it

a. is positively charged.
b. contains nearly all of the atoms mass.
c. is very dense.
d. contains nearly all of the atoms volume.

1. the element boron has two naturally - occurring isotopes - one with an atomic mass of 10.01 and another with an atomic mass of 11.01. given the information provided on the periodic table, which do you think is the most abundant isotope?

a. the one with an atomic mass of 10.01.
b. the one with an atomic mass of 11.01.
c. they are both equally as abundant.
d. not enough information is provided to answer this.

1. an element with 5 protons, 6 neutrons, and 8 electrons has an atomic number of ____.

a. 5 b. 6 c. 8 d. 11

1. an element with 5 protons, 6 neutrons, and 8 electrons has a mass number of ____.

a. 5 b. 6 c. 8 d. 11

1. how many valence electrons does an atom of magnesium typically have?

a. 2 b. 3 c. 12 d. 24

1. how many valence electrons does an atom of aluminum typically have?

a. 2 b. 3 c. 13 d. 27

1. the name of the force that is able to overcome the repulsive force between protons in an atom is the ____.

a. weak nuclear force b. strong atomic force
c. strong nuclear force d. electromagnetic force

1. the number of energy levels an atom will have is based on the number of ____ it has.

a. protons b. neutrons c. electrons d. quarks

1. which of the following would not be found in the nucleus of an atom?

a. protons b. neutrons c. electrons d. quarks

1. which statement about the arrangement of the periodic table is not true?

a. noble gases are on the right side of the periodic table.
b. metals are found on the right side of the periodic table.
c. halogens are on the right side of the periodic table.
d. transition metals are in the center of the periodic table.

1. what kind of charge does an ion have?

a. positive b. negative c. neutral d. can be a or b

1. which of the following elements would be the best conductor of electricity?

a. bromine b. silicon c. nickel d. krypton

Explanation:

1. In a neutral atom, the number of protons equals the number of electrons. So for an atom with 8 protons, it should have 8 electrons, and neutrons can vary.
2. The number of protons determines the identity of an element as it is the atomic - number.
3. The nucleus is positively charged, contains nearly all the atom's mass and is very dense, but it does not contain nearly all of the atom's volume.
4. The atomic mass on the periodic table of boron is approximately 10.81, which is closer to 11.01, so the isotope with atomic mass 11.01 is more abundant.
5. The atomic number is equal to the number of protons.
6. The mass number is the sum of protons and neutrons (5 + 6=11).
7. Magnesium has an atomic number of 12, and its electron - configuration shows 2 valence electrons.
8. Aluminum has an atomic number of 13, and its electron - configuration shows 3 valence electrons.
9. The strong nuclear force overcomes the repulsive force between protons in the nucleus.
10. The number of energy levels is related to the number of electrons.
11. Electrons are found outside the nucleus.
12. Metals are found on the left - hand side of the periodic table, not the right.
13. Ions can be positively or negatively charged.
14. Nickel is a metal and metals are good conductors of electricity. Bromine is a non - metal, silicon is a semi - conductor, and krypton is a noble gas.

Answer:

1. B. 9 neutrons and 8 electrons
2. A. protons
3. D. contains nearly all of the atom’s volume
4. B. The one with an atomic mass of 11.01
5. A. 5
6. D. 11
7. A. 2
8. B. 3
9. C. strong nuclear force
10. C. electrons
11. C. electrons
12. B. Metals are found on the right side of the periodic table
13. D. Can be A or B
14. C. Nickel