Unit 5 Atom and Periodic Table Post Test

Select the correct answer. Which of these elements is a noble gas?

• hydrogen (H)

• barium (Ba)

• nitrogen (N)

• krypton (Kr)

• bromine (Br)

Which option describes a similarity and a difference between isotopes of an element?

• same atomic number; different number of protons

• same number of protons; different atomic number

• same atomic number; different mass number

• same mass number; different atomic number

• same number of neutrons; same number of protons

Select the correct answer. The image shows a portion of the periodic table. Which two elements have similar characteristics?

• neon and fluorine

• chlorine and sulfur

• fluorine and chlorine

• oxygen and chlorine

• argon and fluorine

Select the correct answer. Identify Bohr's model of the atom. His model describes the reactivity of an element based on its number of valence electrons.

• A

• B

• C

• D

Select the correct answer. The frequency of a given region of the electromagnetic spectrum is more than 3 x 10^19 HZ. Note that the speed of light is 2.998 x 10^8 m/s. Which waves are found in this region?

• gamma rays

• visible light

• microwaves

• radio waves

• x-rays

Thallium consists of 29.5% Tl-203 and 70.5% Tl-205. What is the relative atomic mass of thallium?

• 203 amu

• 204 amu

• 203.5 amu

• 205.3 amu

• 204.4 amu

In the periodic table of elements, what do all of the elements in group 2 have in common?

• An atom of each element can hold up to eight electrons in its outer energy level.

• An atom of each element can hold up to six electrons in its outer energy level.

• Each element is an alkaline earth metal.

• Each element is a halogen.

• Each element is dull, brittle, and breaks easily.

Select the correct answer. Which atomic model proposed that electrons move in specific orbits around the nucleus of an atom?

• Dalton’s atomic model

• Thomson’s atomic model

• Rutherford’s atomic model

• Bohr’s atomic model

• quantum atomic model

Select the correct answer. Which of these elements is a metal?

• hafnium (Hf)

• radon (Rn)

• silicon (Si)

• sulfur (S)

• selenium (Se)

Select the correct answer. The wavelength of a specific photon in the x-ray is 5 x 10^-9 meters. Given that the speed of light is 2.998 x 10^8 m/s, what would be the frequency of this x-ray?

• 14.99 x 10^-1 HZ

• 0.5996 x 10^17 HZ

• 1.499 x 10^2 HZ

• 0.5996 x 10^17 HZ

• 1.499 x 10^4 HZ