Chapter 6 Test on Atomic Structure and Chemical Bonds
(Questions 1-44 are worth 2 pts each. Questions 45 & 46 are 6 pts each, and there are 3 ExCr for 1 pt. each)
1. The chemical bond formed when two atoms share electrons is called a(n)
D)
covalent bond.
2. In which of these compounds is the bond between the atoms polar covalent bond?
C)
H2O
3. A molecule is a ____.
C) neutral group of atoms held together by covalent bonds.
4. In drawing a Lewis structure (also know as an electron dot diagram), each atom in the Alkali
Metal group should be surrounded by __.
D)
1 electrons.
5. Chemical bonds formed by the attraction of oppositely charged ions are called __.
A) ionic bonds
6. A phosphorus atom needs to gain _______ electrons to achieve a noble gas configuration.
A) 3
7. A chlorine atom has 17 protons and 18 neutrons. How many electrons does it have?
D)
17
8. The __________ an energy level is from the nucleus, the __________ electrons it can hold.
A)
farther, more
9. How many electrons does an atom of carbon have in its outer energy level?
C)
4
10. A(n) __________ is a force that holds two atoms together.
C)
chemical bond
11. What do lithium, sodium, and potassium have in common?
D)
They are all Group I elements.
12. Which of the following is NOT true of the elements in Group 18?
A)
They are all metalloids.
13. What do atoms of boron and aluminum have in common?
D)
They have three electrons in their outer energy levels.
14. A(n) __________ is a method of representing atoms and the electrons in their valence energy
levels.
A) electron dot diagram or Lewis Structure
15. A(n) __________ is an atom that has gained or lost an electron and is no longer neutral.
B)
ion
16. A double bond is one in which __________.
B)
atoms share two pairs of electrons
17. In the formula H2O, what does the number 2 indicate?
A)
There are two atoms of hydrogen in this molecule.
18. Which describes the change in the magnesium's electron distribution when magnesium
chloride forms? (picture to the right)
D)
One electron is lost to each chlorine atom.
19. What is the maximum number of electrons that can be in an atom's 2nd energy level?
B)
8
20. What is the correct way to write the formula for hydrogen fluoride shown in the illustration?
B)
HF
21. At the center of an atom is a nucleus containing ________.
D) protons and neutrons
22. When an atom gains an electron and becomes negatively charged, we refer to it as a(n)
A) negative ion (because it has more electrons than protons)
23. A molecule consisting of two hydrogen atoms joined in a covalent bond would be written as _.
B) H2
24. For a neutral atom of an element, the number of _____ is always the same.
B) protons and electrons
25. A sodium atom that is positively charged is written as ___.
B) Na+
26. What term refers to a neutral particle formed when atoms share electrons?
B)
molecule
27. Which group of elements in the periodic table has naturally stable energy levels?
B)
noble gases
28. Halogens are which group on the periodic table?
C)
Group 17
29. A molecule of hydrogen chloride is polar because ______.
D) the chlorine attracts the shared electrons more strongly than does the
hydrogen atom.
30. Which element would be most likely to lose electrons in a chemical bond?
A) Lithium
31. Which element would be most likely to gain electrons in a chemical bond?
B) Chlorine
32. Noble gasses do not readily bond with other elements because __.
A) They already have a full outer shell
33. What term is used for the electrons in the outer most shell or energy level?
A) Valence electrons
34. A row on the periodic table is called a
A) Period
35. A column on the periodic table is all of the following EXCEPT
A) called a family or group
B) tells the number of outer shell electrons
C) have elements with similar chemical properties because they have the same # of valence eD) have elements with the same number of energy shells
36. (TRUE) Bonds between metal and metal are called metallic bonds.
37. (TRUE) When writing chemical formulas, if no subscript is present, the number of atoms of
that particular element is automatically one.
38. Electrons closer to the nucleus have (lower) amounts of energy than electrons which are
farther away from the nucleus which are easier to lose.
39. What is the chemical formula for Dihydrogen monoxide? H2O
40. How many atoms of Fluorine are there in CF4? FOUR
41. What element has an atomic number of 20? Calcium or Ca
42. An atom has an atomic mass of 32.065 and an atomic number of 16. How many neutrons
does it have? Round 32.065 to 32 and then subtract the Atomic # which is 16. Therefore the
answer is 32-16= 16 neutrons
43. What is the element mentioned in the previous question (#34)? Silicon
44. What element has atoms with 2 energy shells and 3 valence electrons? Boron
45 (6 points) What makes an ionic compound different from a covalent compound? The main
idea is that ionic compounds transfer electrons (between a metal and non-metal) which make
them charged ions that are strongly attracted to each other. Covalent bonds involve sharing
electrons between two non-metals.
45. (6 points) Draw the Lewis electron structure (electron dot) for the chlorine atom.
Extra Credit
I. An ionic salt is made up of __________ and __________ lined up in a regular pattern.
B)
positive metal ions, negative nonmetal ions
II. Based on what you know about sodium chloride, which of the following elements would you
expect to form an ionic salt? (Hint: Sodium is a Alkali metal and Chloride is a halogen)
A)
potassium and iodine
III. Define the electron cloud: Electron cloud is the group of electrons revolving around the
nucleus of an atom; a cloudlike group of electrons. In the electron cloud model electrons are no
longer depicted as particles moving around the nucleus in a fixed orbit. Instead, we don’t know
exactly where they are. Therefore, we describe their probable location around the nucleus only as a
‘cloud’.