Consider the composition of each species below. Which is an anion?

• 9 protons, 10 neutrons, 10 electrons

• 11 protons, 12 neutrons, 11 electrons

• 12 protons, 12 neutrons, 12 electrons

• 13 protons, 14 neutrons, 10 electrons

Tags

NGSS.HS-PS1-1

Energy levels for an electron in a hydrogen atom are

• evenly spaced.

• farther apart near the nucleus.

• closer together near the nucleus.

• arranged randomly.

Which is related to the number of electrons in the outer main energy level of the elements from the alkali metals to the halogens?

I. Group number

II. Period number

• I only

• II only

• Both I and II

• Neither I nor II

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

How do bond length and bond strength change as the number of bonds between two atoms increases?

• Bond length increases, Bond strength increases

• Bond length increases, Bond strength decreases

• Bond length decreases, Bond strength increases

• Bond length decreases, Bond strength decreases

Which of the following is true for CO₂?

• C=O bond polar; CO₂ molecule non-polar

• C=O bond non-polar; CO₂ molecule polar

• C=O bond polar; CO₂ molecule polar

• C=O bond non-polar; CO₂ molecule non-polar

The molar masses of C₂H₆, CH₃OH and CH₃F are very similar. How do their boiling points compare?

• C₂H₆ < CH₃OH < CH₃F

• CH₃F < CH₃OH < C₂H₆

• CH₃OH < CH₃F < C₂H₆

• C₂H₆ < CH₃F < CH₃OH

What is the correct number of each particle in a fluoride ion, ¹⁹F^– ?

• protons 9, neutrons 10, electrons 8

• protons 9, neutrons 10, electrons 9

• protons 9, neutrons 10, electrons 10

• protons 9, neutrons 19, electrons 10

Which statement is correct for the emission spectrum of the hydrogen atom?

• The lines converge at lower energies.

• The lines are produced when electrons move from lower to higher energy levels.

• The lines in the visible region involve electron transitions into the energy level closest to the nucleus.

• The line corresponding to the greatest emission of energy is in the ultraviolet region.

Tags

NGSS.HS-PS4-3

How many valence electrons are present in an atom of an element with atomic number 16?

• 2

• 4

• 6

• 8

Tags

NGSS.HS-PS1-1

A certain sample of element Z contains 60% of 69Z and 40% of 71Z. What is the relative atomic mass of element Z in this sample? Round to 3 sig figs and use ONLY THE NUMBERS, NO UNITS