Review for Chem Fall Sem Exam 2024

Rubidium has two common isotopes, ⁸⁵Rb and ⁸⁷Rb. If the abundance of ⁸⁵Rb is 72.25 and the abundance of ⁸⁷Rb is 27.8%, what is the average atomic mass of rubidium?

• 61.37%

• 85.56%

• 24.18%

• 58.21%

Tags

NGSS.HS-PS1-8

Which elements have both metallic and nonmetallic properties?

• metalloids

• alkali metals

• transition metals

• rare earth metals

Using the trend for electronegativity, what is the MOST ELECTRONEGATIVE element?

• H

• K

• F

• Ts

How many electrons can fit in the 2nd energy level?

• 2

• 4

• 8

• 32

Describe the PRESENT setup of the periodic table.

• It is arranged by increasing atomic mass

• It is arranged by increasing atomic number

• It is arranged by decreasing atomic number

• It is arranged alphabetically by element symbol

When a ground state atom is heated, it reaches an excited state. When does it emit a photon of light of various wavelengths?

• on the return from excited state to ground state

• when the electron is jumping from ground to energy state via energy levels

• when the heat/flame burns out

• it is not able to emit light at this point

Tags

NGSS.HS-PS4-3

What determines similar chemical and physical properties in a group of elements?

• oxidation state

• atomic mass

• valence electrons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the percentage of cobalt in cobalt (II) fluoride (CoF₂)?

• 33.2%

• 60%

• 75.6%

• 45.5%

In which type of bond will the attraction be unequal, due to electrons held more closely by one atom?

• polar ionic bond

• polar covalent bond

• nonpolar ionic bond

• nonpolar covalent bond

What is 6.02 x 10²³ particles?

• 10 moles

• the conversion for empirical formula

• Avogadro’s constant

• a factor in percent composition