LSU Biology 1201 Exam 1 Gregg Updated Actual Questions and Correct Answers ()

LSU Biology 1201 Exam 1 Gregg Updated Actual Questions and
Correct Answers (2026-2027)

Question 1.
organisms are composed of _______________

Correct Answer: matter


Question 2.
anything that takes up space and has mass

Correct Answer: matter


Question 3.
a substance that cannot be broken down to other substances by chemical reactions
example: hydrogen

Correct Answer: element


Question 4.
a substance consisting of two or more elements in a fixed ratio example: water (H2O)

Correct Answer: compound


Question 5.
the smallest unit of matter that still retains the properties of an element

Correct Answer: atom


Question 6.
atoms are composed of subatomic particles. list the subatomic particles and their charges

Correct Answer: neutron (no charge), proton (positive charge), electron
(negative charge)


Question 7.
neutrons and protons form the ____________

Correct Answer: atomic nucleus


Question 8.
neutron mass and proton mass are almost identical and are measured in ____________

Correct Answer: daltons

,Question 9.
the number of protons in an element's nucleus

Correct Answer: atomic number


Question 10.
the sum of protons plus neutrons in the nucleus of an element

Correct Answer: mass number


Question 11.
the atom's total mass, can be approximated by the mass number

Correct Answer: atomic mass


Question 12.
two atoms of an element that differ in the number of neutrons

Correct Answer: isotope


Question 13.
isotopes that decay spontaneously, giving off particles and energy

Correct Answer: radioactive isotopes


Question 14.
an electron's state of potential energy is called its _________

Correct Answer: energy level/electron shell 1st shell max: 2 electrons 2nd shell
max: 8 electrons 3rd shell max: 8 electrons


Question 15.
when electrons move from a lower energy level to a higher energy level, energy is
_________

Correct Answer: absorbed


Question 16.
when electrons move from a higher energy level to a lower energy level, energy is ________

Correct Answer: lost

,Question 17.
electrons located in the outermost, or valence shell; chemical behavior of the atom is
determined by these electrons

Correct Answer: valence electrons


Question 18.
electrons with a full valence shell are ____________

Correct Answer: chemically inert


Question 19.
atoms with __________ valence shells can share or transfer valence electrons with certain
other atoms

Correct Answer: incomplete


Question 20.
attractions that hold atoms close together

Correct Answer: chemical bonds


Question 21.
the sharing of a pair of valence electrons by 2 atoms; the shared electrons count as a part
of each atom's valence shell example: H2 hydrogen molecule

Correct Answer: covalent bond


Question 22.
consists of two or more atoms held together by covalent bonds example: water (H2O) 2
hydrogen atoms + 1oxygen atom

Correct Answer: molecule


Question 23.
the sharing of one pair of valence electrons

Correct Answer: single covalent bond


Question 24.
the sharing of two pairs of electrons

Correct Answer: double covalent bond

, Question 25.
the notation used to represent atoms and bonding

Correct Answer: structural formula




Question 26.
another name for an atom's bonding capacity

Correct Answer: valence


Question 27.
a combination of two or more different elements

Correct Answer: compound


Question 28.
an atom's attraction for the electrons in a covalent bond

Correct Answer: electronegativity


Question 29.
the more electronegative an atom is, the more _____ it pulls shared electrons toward itself

Correct Answer: strongly


Question 30.
a covalent bond in which the atoms share the electron equally

Correct Answer: nonpolar covalent bond