Question

1. which of the following elements would be the most reactive? a. bromine b. silicon c. nickel d. krypton
2. which of the following elements would be the least reactive? a. bromine b. silicon c. nickel d. krypton
3. the nucleus of isotope a of an element has a larger mass than isotope b of the same element. the number of neutrons in the nucleus of isotope a is ______ the number of neutrons in the nucleus of isotope b. a. less than b. greater than c. the same as
4. the nucleus of isotope a of an element has a larger mass than isotope b of the same element. the number of protons in the nucleus of isotope a is ______ the number of protons in the nucleus of isotope b. a. less than b. greater than c. the same as
5. an atom is electrically neutral when its a. neutrons balance the protons and electrons. b. nuclear forces stabilize the charges. c. numbers of protons and neutrons are equal. d. numbers of protons and electrons are equal.
6. the force between the nucleus and the electron cloud is ____. the force between the electrons in the electron cloud is ____. a. repulsive; attractive b. attractive; repulsive c. repulsive; repulsive d. attractive; attractive

for #21 - 32, match the vocabulary terms with their correct definition.

1. atom a. atoms of the same element with different masses.
2. atomic number b. this contributes to the mass of an atom but not its charge.
3. isotope c. this differs amongst isotopes and thus must be included in their notation.
4. proton d. the smallest unit of an element that still retains its properties.
5. neutron e. this is a row on the periodic table.
6. electron a. the periodic table is arranged by this.
7. quark b. this is a charged atom.
8. mass number c. the weighted average of all of the different isotopes of an element.
9. average atomic mass d. the number of these determines the identity of an atom.
10. group e. the number of these determines the charge and bonding behavior of an atom.
11. period a. this can also be referred to as a family.
12. ion b. the attraction between these holds the nucleus together.
13. a bohr model is a helpful tool for visualizing the structure of the atom. what is one major shortcoming of the model that does not accurately represent an atoms structure. a. it is a 2d representation of a 3d model b. it does not accurately depict the nucleus c. it does not include the electrons d. it only depicts electrons and protons

for questions 34 - 39: identify the following as a metal (a), nonmetal (b), or metalloid (c).

1. he
2. h
3. zn
4. k
5. as
6. cl

Explanation:

1. Bromine is a halogen and highly reactive among the given elements. Halogens have 7 valence - electrons and tend to gain an electron to achieve a stable octet.
2. Krypton is a noble gas with a full outer - electron shell, making it very stable and least reactive.
3. The mass of an isotope is mainly due to protons and neutrons. If isotope A has a larger mass than isotope B of the same element, it has more neutrons since the number of protons is the same for isotopes of the same element.
4. Isotopes of the same element have the same number of protons.
5. An atom is electrically neutral when the number of positively - charged protons equals the number of negatively - charged electrons.
6. The nucleus is positively charged and the electron cloud is negatively charged, so the force between them is attractive. Electrons in the electron cloud repel each other as they have the same charge.
7. An atom is the smallest unit of an element that still retains its properties.
8. The periodic table is arranged by atomic number.
9. Isotopes are atoms of the same element with different masses.
10. The number of protons determines the identity of an atom.
11. Neutrons contribute to the mass of an atom but not its charge.
12. The number of electrons determines the charge and bonding behavior of an atom.
13. Quarks are sub - atomic particles that make up protons and neutrons.
14. The mass number is the sum of protons and neutrons in an atom.
15. The average atomic mass is the weighted average of all of the different isotopes of an element.
16. A group in the periodic table can also be referred to as a family.
17. A period is a row on the periodic table.
18. An ion is a charged atom.
19. The Bohr model is a 2D representation of a 3D model, which is a major shortcoming.

34 - 39: Helium (He) is a nonmetal, hydrogen (H) is a nonmetal, zinc (Zn) is a metal, potassium (K) is a metal, arsenic (As) is a metalloid, chlorine (Cl) is a nonmetal.

Answer:

1. A. Bromine
2. D. Krypton
3. B. greater than
4. C. the same as
5. D. numbers of protons and electrons are equal
6. B. attractive; repulsive
7. D. The smallest unit of an element that still retains its properties.
8. A. The periodic table is arranged by this.
9. A. Atoms of the same element with different masses.
10. D. The number of these determines the identity of an atom.
11. B. This contributes to the mass of an atom but not its charge.
12. E. The number of these determines the charge and bonding behavior of an atom.
13. (No correct match provided in the given options as quarks are sub - atomic particles that make up protons and neutrons)
14. (No correct match provided in the given options as mass number is the sum of protons and neutrons in an atom)
15. C. The weighted average of all of the different isotopes of an element.
16. A. This can also be referred to as a family.
17. E. This is a row on the periodic table.
18. B. This is a charged atom.
19. A. It is a 2D representation of a 3D model
20. B. nonmetal
21. B. nonmetal
22. A. metal
23. A. metal
24. C. metalloid
25. B. nonmetal