Unit 5 and chem

When compared with the energy of an electron in the second shell of a carbon (C) atom? The energy of an electron in the first shell of a carbon atom is a. Less b. Greater c. The same

less

When an electron in an atom absorbs energy, it a. moves to a higher energy level b. emits light c. moves to its ground state d. none of the above

moves to a higher energy level

When an atom loses an electron, it becomes a a. neutral atom b. neutral ion c. positive ion d. negative ion

positive

Given that fluorine's atomic number is 9 and that fluorine has 2 electrons in its lowest orbital, how many valence electrons does fluorine have? a. 7 b. 9 c. 11 d. 18

7

In the Quantum Mechanical or the wave- mechanical model of the atom, an orbital is a region of space in an atom where there is a. A high probability of finding a proton b. A high probability of finding an electron c. A specific path that an electron orbits d. A specific path that a proton orbits

A high probability of finding an electron

The elements that are characterized by having only five electrons in the P sublevel belong to which family of elements?

Halogens

How did Mosely improve Mendeleev's table?

He arranged the table according to increasing atomic number.

What was the major flaw with Menedeleev's periodic table?

He sorted it according to increasing atomic mass.

Why does the trend in atomic radius occur?

In periods, protons added to the nucleus increase the effective nuclear charge; in groups, valence electrons in larger atoms feel less of the attractive force from the nucleus.

Where are the most reactive elements found?

In the bottom left and top right corner of the periodic table.

At room temperature (i.e. 20-25 0 C), chlorine exists as a gas, bromine exists as a liquid, and iodine exists as a solid. The physical states of these elements indicate that melting point:

Increases from top to bottom within group VIIA or 17 elements

Which are arranged according to increasing size? Li+, Li, Be

Li +1 , Be, Li

Which elements are arranged according to increasing ionization energy?

Li, Be, B, C

Which set of symbols represent atoms with valence electrons in the same energy level (i.e. row or period)? a. Li, C, F b. O, Se, Po c. Li, Mg, Rb d. Fe, Ru, Os

Li, C, F

How many electrons are contained in the Fe 2+ ion? a. 26 b. 28 c. 56 d. 24

24

What is the total number of valence electrons in an atom of aluminum in the ground state? a. 6 b. 8 c. 3 d. 4

3

Ar

Ar 1s2 2s2 2p6 3s2 3p6

Which of the following is NOT true concerning electronegativity?

Electronegativity increases as you travel down a group.

Which electronic transition represents an emission of energy? a. From 2 nd to 3 rd shell b. From 1 nd to 2 st shell c. From 3 rd to 2 nd shell d. From 3 rd to 5 st shell

From 3rd to 2nd shell

A neutral calcium atom has 20 electrons. How many electrons does a calcium ion have? a. 2 b. 18 c. 20 d. 22

18

Chlorine forms a -1 ion. How many electrons does a chloride ion have? a. 1 b. 16 c. 17 d. 18

18

What is the electron configuration of Mg 2+ ? a. 1s 2 2s 2 2p 6 3s 1 3p 1 b. 1s 2 2s 2 2p 6 3s 2 c. 1s 2 2s 2 2p 6 3s 1 d. 1s 2 2s 2 2p 6

1s2 2s2 2p6

An element has an electron configuration of 1s 2 2s 2 2p 6 3s 2 . Which of these will be in the same group (i.e. column) as this element? a. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 b. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 c. 1s 2 2s 2 2p 6 3s 1 d. 1s 2 2s 2 2p 6 3s 2 3p 6

1s2 2s2 2p6 3s2 3p6 4s2

Which of these elements is found in a family with the following valence electron configuration: ns 2 np 1 ? a. Al b. Sr c. Si d. Sb

Al

Which of the following properties decreases from left to right across a period?

Atomic Radius

Which of the following correctly describes the vertical trend in atomic radius as you move down a group?

Atomic radius increases, because the size of the orbitals is getting larger.

outer shell configuration Ba Br

Ba 6s2 Br 4s2 4p5

Noble gas shortcut Br [Ar] 4s 2 3d 10 4p 5 Rb [Kr] 5s 1

Br [Ar] 4s2 3d10 4p5 Rb [Kr] 5s1

What is the main similarity among the elements in Group 2?

Chemical properties

Arrange the elements, Al, S, Na and Cl in order from smallest atomic radius to largest atomic radius.

Cl, S, Al, Na

According to the periodic table, which of the following series of elements is ordered according to decreasing reactivity?

Cs, Mg, Si, He

Which of these elements is the most chemically active (i.e. most reactive)?

F

Arrange the following according to increasing ionic size. F - , Cl - , Br - , I -

F - , Cl - , Br - , I -

Fe

Fe 1s2 2s2 2p6 3s2 3p6 4s2 3d6

Which particle has the same electron configuration as a nitrogen ion? a. Chloride ion b. Lithium ion c. Neon atom d. Argon atom

Neon atom

Arrange the elements, S, O, Te and Po in order from smallest atomic radius to largest atomic radius.

O, S, Te, Po

Which of these pairs of elements would be expected to have similar chemical properties?

Phosphorus and Arsenic, because they have the same number of valence electrons.

What do neon, argon, krypton, and xenon have in common? a. They are metalloids. b. They belong to the same period. c. Their outermost energy levels are full. d. They share the same number of protons.

Their outermost energy levels are full.

True/ False. Choose a for true, b for false. a. 46. The nuclear charge of an atom increases when more protons are added to the nucleus. a. 47. Si is a metalloid. b. 48. Noble gases have high electronegativities because they are already stable. b. 49. Al is a metalloid. a. 50. The element found in period 5, group 11 is Ag.

True/ False. Choose a for true, b for false. a. 46. The nuclear charge of an atom increases when more protons are added to the nucleus. a. 47. Si is a metalloid. b. 48. Noble gases have high electronegativities because they are already stable. b. 49. Al is a metalloid. a. 50. The element found in period 5, group 11 is Ag.

In comparison to an atom of 75 As in the ground state, an atom of 80 Br in the ground state has a. Two fewer valence electrons b. Five more protons c. Three fewer neutrons d. Two more valence electrons

Two more valence electrons

Why does the trend in ionization energy exist?

a. In groups, larger atoms feel less of an effective nuclear charge, making electrons easy to remove. b. In groups, a larger shielding effect makes electrons easy to remove.