BIOS251-EXAM 1 (WEEK 2-CHEM)
QUESTIONS WITH CORRECT ANSWERS
2025
Element CORRECT ANSWER
a form of matter that cannot be broken down any further by chemical reactions
Atom CORRECT ANSWER
the smallest particle of an element that still has the properties of that element
Protons CORRECT ANSWER +1 charge
Neutron CORRECT ANSWER neutral charge
Electrons CORRECT ANSWER much smaller mass than protons or neutrons; -1 charge
Atomic number CORRECT ANSWER number of protons in an atom
Mass number CORRECT ANSWER total number of protons and neutrons in an atom
Atomic weight CORRECT ANSWER average mass of an atom of that element
Molecules CORRECT ANSWER
atoms can react with either atoms of the same element or atoms of different elements to create molecul
es
-
molecules are atoms held together by electron based interactions called intermolecular bonds (electrons
interact with other atoms to form bondsgsince they are the outermost subatomic particle)
Ions CORRECT ANSWER
are atoms or molecules with an electrical charge which arises from an imbalance of protons and electron
s
, Electrolytes CORRECT ANSWER are any substance that gives off or forms ions when dissolved in
water
Ionic bonding CORRECT ANSWER - typically btw metals and nonmetals
- form btw cations (pos charge) and anions (neggcharge)
- forms by the transfer of electrons
Covalent bonding CORRECT ANSWER - typically btw nonmetals
- nonmetals form covalent bonds by sharing electrons btw them, as opposed to transferring electrons
-
when one of thegatomsgin a bond has a higher affinity for electrons than the other (electronegativity), an
d a polar covalent bond is formed where electrons are shared unequally
-
when both nonmetals have similar electron affinity, a nonpolar covalent bond is formed, where the elect
rons in the covalent bond are shared equally
Metallic bonding CORRECT ANSWER - typically btw metals
- elements broadly classified as either metals or nonmetals; grouped on the periodic table as such
Mixture CORRECT ANSWER
a combination of more than one compound, physically mixed together, two types of mixtures
1. homogenous
2. heterogenous
Homogenous mixture CORRECT ANSWER
do not separate over time and cannot be separated by most membranes, also known as solutions
Heterogenous mixture CORRECT ANSWER not uniform in their composition
Solution CORRECT ANSWER -
cannot be visually distinguished from solvent or one another; cannot be separated by a membrane; usua
lly transparent
QUESTIONS WITH CORRECT ANSWERS
2025
Element CORRECT ANSWER
a form of matter that cannot be broken down any further by chemical reactions
Atom CORRECT ANSWER
the smallest particle of an element that still has the properties of that element
Protons CORRECT ANSWER +1 charge
Neutron CORRECT ANSWER neutral charge
Electrons CORRECT ANSWER much smaller mass than protons or neutrons; -1 charge
Atomic number CORRECT ANSWER number of protons in an atom
Mass number CORRECT ANSWER total number of protons and neutrons in an atom
Atomic weight CORRECT ANSWER average mass of an atom of that element
Molecules CORRECT ANSWER
atoms can react with either atoms of the same element or atoms of different elements to create molecul
es
-
molecules are atoms held together by electron based interactions called intermolecular bonds (electrons
interact with other atoms to form bondsgsince they are the outermost subatomic particle)
Ions CORRECT ANSWER
are atoms or molecules with an electrical charge which arises from an imbalance of protons and electron
s
, Electrolytes CORRECT ANSWER are any substance that gives off or forms ions when dissolved in
water
Ionic bonding CORRECT ANSWER - typically btw metals and nonmetals
- form btw cations (pos charge) and anions (neggcharge)
- forms by the transfer of electrons
Covalent bonding CORRECT ANSWER - typically btw nonmetals
- nonmetals form covalent bonds by sharing electrons btw them, as opposed to transferring electrons
-
when one of thegatomsgin a bond has a higher affinity for electrons than the other (electronegativity), an
d a polar covalent bond is formed where electrons are shared unequally
-
when both nonmetals have similar electron affinity, a nonpolar covalent bond is formed, where the elect
rons in the covalent bond are shared equally
Metallic bonding CORRECT ANSWER - typically btw metals
- elements broadly classified as either metals or nonmetals; grouped on the periodic table as such
Mixture CORRECT ANSWER
a combination of more than one compound, physically mixed together, two types of mixtures
1. homogenous
2. heterogenous
Homogenous mixture CORRECT ANSWER
do not separate over time and cannot be separated by most membranes, also known as solutions
Heterogenous mixture CORRECT ANSWER not uniform in their composition
Solution CORRECT ANSWER -
cannot be visually distinguished from solvent or one another; cannot be separated by a membrane; usua
lly transparent
