chapter 6
If a neutral atom loses one electron, what is the electrical charge of the atom?
+1
How many valence electrons does bromine (Br, atomic no. = 35) have?
7
If a neutral atom gains two electrons, what is the electrical charge of the atom?
-2
Which of the following elements will most likely form an ion with a +1 charge?
-Na -Li
Which of the following is a positive ion?
-Na+ -Mg2+ -Ca2+ -Al3+
Which of the following is NOT an ion?
-O2 -NO2
Which of the following is a negative ion?
-S2− -O2−
What does the line in the following example actually represent? H-H
-a covalent bond -a shared pair of electron
How many more electrons can fit within the valence shell of a hydrogen atom?
1
The number of nonbonding pairs in the ammonia molecule is ________.
1
How many covalent bonds would the following atom usually form?
3
How many valence electrons does boron (B, atomic no. = 5) have?
3
How many valence electrons does gallium (Ga, atomic no. = 31) have?
3
What would be the chemical formula for the ionic compound aluminum chloride?
AlCl3
How do the electron-dot structures of elements in the same group in the periodic table compare with one another?
Elements of the same group have the same number of valence electrons.
Which of the following is a covalent compound composed of nonpolar covalent bonds?
H2
What is the valence shell?
It is the outermost shell of electrons in an atom.
Which of the following contains an ionic bond?
MgCl2
Take money away from your bank account and the bank will show a negative credit. Take an electron away from an atom, however, and the atom shows up positive. Explain.
Neutral atoms contain identically charged but oppositely signed protons and electrons. Removing one of the negative electrons results in an excess of positively charged protons.
Which of the following elements has six valence electrons?
O
What it the main difference between an ionic and a covalent bond?
One is the sharing of a pair of electrons, the other is the transfer of at least one electron.
How is the number of unpaired valence electrons in an atom related to the number of bonds that the atom can form?
The number of unpaired valence electrons in an atom is the same as the number of bonds that the atom can form.
Which of the following statements is true?
The valence shell gives us the electron dot structure.
Why do you NOT need to memorize the type of ion each atom tends to form?
This information is spelled out in the periodic table.
What is a molecule?
a group of atoms that are held together by covalent bonds
What needs to be done to convert a neutral nitrogen atom into an N3- species?
add three electrons
Which of the following would be an ion with a double positive charge?
an Mg atom that loses two electrons
Which of the following would be a negative ion with a single charge?
an atom with 11 protons and 12 electrons
Calcium fluoride, CaF2, is an example of ________.
an ionic compound
Electron-dot structures are needed to help us understand which kinds of chemical bonds?
both ionic and covalent
Which of the following is the correct electron dot structure for chlorine (atomic no. = 17)?
d
Which of the following is the correct electron dot structure for carbon (atomic no. = 6)?
e
The concept of a chemical bond is ________.
how two or more atoms are held together
The fundamental unit of most covalent compounds is the _______.
molecule
Which of the following best describes ionic bonding?
one atom giving up some of its electrons to another atom
The neon atom tends NOT to gain any additional electrons because ________.
there is no more room available in its outermost occupied shell
How many covalent bonds would the following generic atom usually form?
would usually not form any covalent bonds