Biological Foundations Quiz 1

All atoms of the same element have the same ______. -number of neutrons. -atomic number. -number of electrons. -atomic mass. -number of ions.

atomic number.

The subatomic particles that are found in the nucleus of an atom are the ________. -protons and electrons. -neutrons and protons. -electrons only. -protons only. -electrons and neutrons.

neutrons and protons.

True or False When a positively charged hydrogen in a water molecule become attracted to the negatively charged oxygen in a nearby water molecule, this is called a ionic bond.

False

Which of the following would be considered a trace element in living things? -Oxygen -Carbon -Nitrogen -Zinc -Hydrogen

Zinc

An ionic bond forms when _______. -an atom gives away or takes in an electron. -an atom gives away or takes in a proton. -a negatively charged ion is attracted to one with a positive charge. -two atoms come close enough to share one or more electrons. -two atoms come close enough to share one or more protons.

a negatively charged ion is attracted to one with a positive charge.

An atom's valence electron shell _________. -is filled when it has three electrons. -determines its chemical reactivity. -determines its atomic mass. -is filled with positively charged particles. -is filled identically for every element.

determines its chemical reactivity.

A covalent bond occurs when _________. -protons are transferred from one atom to another. -neutrons are shared between two atoms to form an isotope. -electrons are shared between two atoms to complete their octets. -the hydrogen of one water molecule is attracted to the oxygen of another water molecule. -electrons are transferred from one atom to another.

electrons are shared between two atoms to complete their octets.

The weak attractions between water molecules are known as _______. -covalent bonds. -hydrogen bonds. -ionic bonds. -positive and negative ions. -no chemical bonding.

hydrogen bonds.

When a sodium atom transfers an electron to a chlorine atom _______. -the sodium atom becomes a positively charged ion. -the chlorine atom becomes a negatively charged ion. -the positive and negative ions will attract each other, forming a crystal if no water is present. -the ions will separate in the presence of water. -all of the above statements are correct.

all of the above statements are correct.

A(n) ________ can be defined as a substance that keeps pH within established limits by taking up excess H+ or OH- in a solution. -equalizer -solute -buffer -acid -base

buffer