Chapter 1: Atomic Structure

Identify all of the items that represent an element and not a molecule. Select all that apply.

• Li

• H

• N₂

• Ne

• CO₂

Which of the following statements about the properties of elements related to an atomic emission spectrum are true? Select all that apply.

• An atomic emission spectrum occurs when an elemetn in the gas state absorbs energy, and emits light which corresponds to the energies of specific electrons

• The light that an element emits is made up of an unlimited number of narrow lines of light that produce several different patterns or atomic emissions spectra for each element.

• An atomic emission spectrum shows the pattern formed when light absorbed by an element is separated into its different component wavelengths.

• The light that an element emits is made up of a limited number of narrow lines of light that produce a unique pattern or atomic emissions spectrum for that element.

• An atomic emission spectrum shows the pattern formed when light emitted by an element is separated into its different component wavelengths

A chemistry graduate student is very skilled at analyzing atomic emission spectra. The print out of her spectrum is printed in black and white. Therefore she has to rely on comparing the widths and positions of spectral lines during analysis. Observe the various atomic emission spectra.

• Hydrogen

• Helium

• Sodium

• Copper

• Strontium

Which pattern(s) may be observed from the arrangement of elements in the periodic table? Select all that apply.

• increasing number of protons

• similarity in the number of their valence electrons

• similarity in their physical and chemical properties

• increasing relative abundance on Earth’s surface

Based on the periodic table, which other element is likely to share common properties with sodium, or Na?

• Ca

• Cs

• Mg

• Ne

Which of the following is a characteristic of the Group 14 elements?

• They have 14 protons.

• They have 14 neutrons.

• They have 4 core electrons.

• They have 4 valence electrons.

An atom of bromine has 35 electrons. These electrons are present in energy shells around the nucleus. What is the electron configuration of bromine?

• 2, 8, 18, 1

• 2, 8, 18, 7

• 2, 8, 18, 35

• 2, 8, 8, 17

Each arrow shows an electron moving from one energy level to another. Which transitions will release energy?

• A and D

• B and C

• only A

• only C

Which of the following statements about the element from which the ribbon was made, are true? Select all that apply.

• It has two valence electrons.

• It belongs to the third group.

• It belongs to the third period.

• It has three valence electrons.

Which other element is likely to show a similar chemical reaction with oxygen as shown by magnesium, and to which group does it belong?

• Ca, it belongs to Group 2

• Na, it belongs to Group 1

• K, it belongs to Group 2

• C, it belongs to Group 1