Review AP Biology Unit 1

What are the four most abundant elements found in living systems?

• nitrogen, carbon, sulfur, and oxygen

• hydrogen, oxygen, nitrogen, and carbon

• hydrogen, oxygen, nitrogen, and carbon dioxide

• hydrogen, oxygen, calcium, and nitrogen

The number of protons in an uncharged atom

• equals the number of electrons in the outer orbital of the atom

• equals the number of electrons

• equals the number of neutrons

• varies with the different isotopes

• determines its mass number

Consider a hypothetical atom with an atomic number of 4 and an atomic mass of 9.0. How many neutrons does this atom have?

• one

• three

• four

• five

• None of the choices is correct.

Tags

NGSS.MS-PS1-1

The chemical characteristics or reactivity of an element depend mostly on the __________.

• mean energy level of its electrons

• degree to which it has more or fewer electrons than protons

• number of electrons in its outermost shell

• number of electron shells present in the atoms

• number of protons plus the number of neutrons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

For most atoms, a stable configuration of electrons is attained when the atom __________.

• has a full number electrons in its outermost shell

• has moved all its electrons to its outermost shell

• achieves a zero net charge

• has as many protons as neutrons

• None of the choices is correct.

When one or more pairs of valence electrons are shared by two neutral atoms, what type of bond is formed?

• an electronegative bond

• a hydrogen bond

• a covalent bond

• a van der Waals bond

• an ionic bond

Tags

NGSS.HS-PS1-1

A covalent bond is likely to be polar if __________.

• the two atoms sharing electrons are of the same element

• it is between two atoms that are both very strong electron donors

• the two atoms sharing electrons are equally electronegative

• one of the atoms sharing electrons is much more electronegative

• it is between two atoms that are both very strong electron acceptors

Ionic bonds form as a result of __________.

• attraction between hydrogen and other atoms that share electrons unequally

• unequal sharing of electrons between atoms

• attraction between ions that have opposite charges

• the asymmetric distribution of electrons in constant motion

• sharing of electron pairs between atoms

What do cohesion, surface tension, and adhesion have in common with reference to water?

• All are properties related to hydrogen bonding.

• All are aspects of a crystalline structure.

• All have to do with ionic interactions.

• All are results of the structure of the hydrogen atom.

• All are produced by covalent bonding.

Tags

NGSS.HS-ESS2-5

Because molecules of water are farther apart in ice than in liquid water, __________.

• ice is denser than liquid water

• ice vaporizes before liquid water does

• ice floats on liquid water

• ice expands when it melts

• All of the choices are correct.