chem 4-6

electron transfer is closely associated with which concept?

the ionic bond model

Electron sharing is closely associated with which concept?

the covalent bond model

Which of the following is a general characteristic of most ionic compounds?

good electrical conductors in the molten state

Representative elements in the same group of the periodic table

have the same number of valence electrons.

The number of valence electrons for representative elements is the same as the periodic-table group number

with the A designation

The maximum number of valence electrons is eight for any element in

Period 2 or higher

How many valence electrons are present in atoms of Li, a Group 1A element?

one

How many dots are present in the Lewis symbol for the element oxygen, a Group 6A element?

six

Which has the most stable of valence electron configurations?

noble gases

How does the octet rule relate to the number 8?

Atoms, during compound formation, frequently obtain eight valence electrons

What is the relationship between the number of protons and electrons for an ion with the symbol Ca2+?

two more protons than electrons

What change in the subatomic particles occurs when an atom of Al is converted to Al3+?

loss of three electrons

What type of ion is formed when an atom loses one or more electrons?

always produces a positive ion

What is the charge of the ion most likely formed from an atom with one valence electron?

1+

What are the charges of the ions formed from magnesium (Group 2A) and fluorine (Group 7A), respectively?

2+, 1-

Which of the following descriptions is CORRECT for two ions that are isoelectronic?

same electrobn configuration

Which atom is isoelectronic with the ion O2-

Ne atom

In forming the ionic compound ‍K2O from K (one valence electron) and O (six valence electrons), how many total electrons does each oxygen atom acquire via electron transfer?

two

In forming an ionic compound from Ca (two valence electrons) and S (six valence electrons), how many calcium atoms are needed to meet the “electron needs” of one S atom?

one

What is the charge of the ion most likely formed from an atom with one valence electron?

1+

What are the charges of the ions formed from magnesium (Group 2A) and fluorine (Group 7A), respectively?

2+ and 1-

Which of the following descriptions is CORRECT for two ions that are isoelectronic?

same electron configuration

Which atom is isoelectronic with the ion O2-

Ne atom

Lewis structure

is a combination of Lewis symbols that represents either the transfer or the sharing of electrons between atoms in chemical bonds. Lewis symbols involve individual elements. Lewis structures involve compounds.

lewis structure 2

1. The Lewis symbols of cations have zero dots. They only contain the element symbol, brackets, and the charge of the ion.

2. The Lewis symbols of anions will have eight dots: a full octet. They contain the element symbol, brackets, the charge of the ion, and eight dots (four pairs).

When magnesium (two valence electrons) combines with chlorine (seven valence electrons), what is the chemical formula for the resulting ionic compound?

MgCl2

three rules to remember when doing ionic compounds

1. The symbol for the positive ions is always written first.

2. The charges on the ions that are present are not shown in the formula. While ionic charges must be known to determine the formula, the charges are not explicitly shown in the chemical formula.

3. The numbers in the formula (the subscripts) give the lowest combining ratio for the ions.