Ch 9 Hw

On a piece of paper, write a Lewis formula for HNO3, assuming that the octet rule holds for the atoms. What is the formal charge of the nitrogen atom in an stabilized structure?

+1 1+5+18=24 5-4-0= 1

On a piece of paper, write a Lewis formula for N2O(NNO), assuming that the octet rule holds for the atoms. What is the formal charge of the nitrogen atom in an stabilized structure?

+1 5-2-3=0 5-4=1

What is the total number of valence electrons for Ga3+?

0

On a piece of paper, write a Lewis formula for ClNO, assuming that the octet rule holds for the atoms. What is the formal charge of the nitrogen atom in an stabilized structure?

0 5+6+7=18 7-1-6=0 6-2-4=0

Arrange the following pair in order of increasing radius: Al, Al^3+

Al^3+<Al The cation is smaller than the neutral atom because it has lost all its valence electrons; hence, it has one less shell of electrons. The electron-electron repulsion is reduced, so the orbitals shrink because of the increased attraction of the electrons to the nucleus.

What is the ground-state electron configuration of a C^-2 ion?

1s2 2s2 2p4

Give the electron configuration for: O^2-

1s2 2s2 2p6

Give the electron configuration for: Ca^2+

1s2 2s2 2p6 3s2 3p6

Give the electron configuration for: K+

1s2 2s2 2p6 3s2 3p6

What is the total number of valence electrons for Ga?

3

Arrange the following pair in order of increasing radius: As^3-, Se^2-, Br-

Br-<Se^2-<As^3- All of these ions have the same number of electrons. The ion with the highest negative charge has the largest radius because there are fewer protons than electrons to pull the electrons towards the nucleus. This trend only works when there are the same number of electrons for all of the species.

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. C, Br

CBr4 carbon tetrabromide

Use Lewis symbols to represent the electron transfer between the following atoms to give ions with noble-gas configurations: Ca and S

Ca has 2 and give both to S which has 6 to complete it

Which of the following ions are isoelectronic? Ca^2+, K+, O^-2

Ca^2+ and K+

Arrange the following pair in order of increasing radius: Cl-,I-,Br-

Cl-<Br-<I- When the charge is the same, ion size increases down a column because electrons are added to shells farther away from the nucleus.

What is the Lewis formula for the following: Cl2

Cl-Cl since both have 7 and 7+7=14 so they both share one

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. C, Br

Covalent Carbon and bromine are both nonmetals; hence, the binary compound is likely to be covalent.

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. N, Br

Covalent Nitrogen and bromine are both nonmetals; hence, the binary compound is likely to be covalent.

What is the Lewis formula for the following: NF3

F-N-F | F (3*7)+5 = 26

Arrange the following in order of increasing electronegativity: Li, Be, Fr

Fr<Li<Be Electronegativity increases from left to right and from bottom to top in the periodic table.

What is the Lewis symbol for Ga^3+

Ga^3+

What is the Lewis formula for the following: H2S

H-S-H (2*1)+6 = 8

Arrange the following in order of increasing electronegativity: In, Ge, Ga

In<Ga<Ge Electronegativity increases from left to right and from bottom to top in the periodic table.

The element X below could be? Has 7 dots in a Lewis Dot Structure

Iodine It is in the group 7A of the periodic table

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. Sr, O

Ionic Strontium is a metal, and oxygen is a nonmetal. The binary compound is likely to be ionic.

What is the Lewis symbol for Ga?

It has 3 dots [Ar] 3d10 4s2 4p1

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. Sr, O

SrO strontium oxide

Arrange the following in order of increasing electronegativity: B, Be, Li

Li<Be<B Electronegativity increases from left to right and from bottom to top in the periodic table.

For each of the following pairs of elements, state whether the binary compound formed is likely to be ionic or covalent. Also, choose the formula and name of the compound. N, Br

NBR3 nitrogen tribromide

Which of the following bonds if least polar on the basis of electronegativities of atoms: H-F, Si-O, S-Cl

S-Cl F-H= 4.0-2.1 = 1.9 O-Si= 3.5-1.8= 1.7 Cl-S= 3.0-2.5 = 0.5 The difference is the smallest therefore it is the least polar

The element X below could be? Has 4 dots in a Lewis Dot Structure

Silicon It is in the group 4A of the periodic table

Below on the left side are models of two atoms, one from a metal, the other from a nonmetal. On the right side are corresponding monoatomic ions of those atoms. Decide which of these ions is the cation and which is the anion.

Small yellow(nonmetal) + Large blue (metal) = Small blue (cation) + Large yellow (anion) The smaller atom on the left (yellow) becomes a larger ion on the right, while the larger atom on the left (blue) becomes the smaller ion on the right. Since cations are smaller than their parent atom, and anions are larger than their parent atom, the cation on the right is the smaller ion (blue), and the anion is the larger ion (yellow). Finally, since metals tend to form cations, and nonmetals form anions, the metal on the left is the larger atom (blue), and the nonmetal is the smaller atom (yellow).

Use Lewis symbols to represent the electron transfer between the following atoms to give ions with noble-gas configurations: Sr and Br

Sr has two and it give both to two Br which have 7 each

Arrange the following ions in order of increasing ionic radius: Sr^2+, Se^2-, Rb+, Br-

Sr^2+<Rb+<Br-<Se^2- Ionic radii increase down any column because of the addition of electron shells. Isoelectronic refers to different species having the same number and configuration of electrons. In any isoelectronic sequence of atomic ions, the ionic radius increases with decreasing atomic number (just as it does for the atoms). In general, across a period the cations decrease in radius. When you reach the anions, there is an abrupt increase in radius, and then the radius again decreases.

Arrange the following pair in order of increasing radius: Te, Te^2-

Te<Te^2- The anion is larger than the neutral atom because it has more electrons. The electron-electron repulsion is greater, so the valence orbitals expand to give a larger radius.