BISC 101 Midterm Actual Exam Study
Questions with 100% Correct Answers
Already Graded A+
1. Protons - ANSWER - have a positive charge
- Number of protons cannot vary so if it were to change then the
element itself is different and will be longer be the same.
the number of neutrons can change, and it will remain the same element.
These are known as isotopes
2. neutrons - ANSWER - have a negative charge
3. Isotope - ANSWER when he number of neutrons charges but the element
remains the same
4. Hydrophilic - ANSWER when a solute dissolved in water ("water loving")
- Polar molecules
5. Hydrophobic - ANSWER substances that do not interact with/ dissolve in
water ("water fearing")
- Nonpolar molecules
6. What properties are correlated with water's structure - ANSWER - cohesion
- adhesion.
- surface tension
,7. Cohesion - ANSWER attraction between like molecules
- water molecules
8. adhesion - ANSWER attraction between unlike molecules
- interaction between water and a solid surface
9. surface tension - ANSWER is the cohesive force caused by attraction
between the molecules at the surface of a liquid
- any force that depresses a water's surface meets with resistance and so
it makes water's surface act like an elastic membrane
10.Electronegativity - ANSWER when atoms of different elements form a
bond by pulling the shared electrons towards their nuclei with varying
strengths.
- From most to least electronegative element: O > N > S ≈ C ≈ H ≈ P
11.What is responsible for an atom's electronegativity? - ANSWER - The
number of protons in the nucleus and the distance between the nucleus and
the valence shell.
12.Oxygen - ANSWER attracts covalently bonded electrons more strongly
than any other atom commonly found in organisms.
,13.Chemical equilibrium - ANSWER when forward and reverse reactions
proceed at the same rate
14.Acids - ANSWER substances that give up protons during chemical
reactions and raise the hydronium ion [water]
- adding an acid to a solution increases the [protons]
15.Covalent bond - ANSWER a strong attraction where two atoms share
electrons (nonmetal and nonmetal)
16.Nonpolar covalent bond - ANSWER a bond that involves equal shared
electrons
17.Polar covalent bond - ANSWER asymmetric sharing of electrons
18.Why is it important to know why electrons in a polar covalent bond spend
most of their time close to the nucleus of the more electronegative atom? -
ANSWER In a water molecule the electrons are not shared equally but are
held tightly by the oxygens nucleus than the hydrogens nucleus.
- Due to the unequal sharing of electrons oxygen will have a partial
negative charge and hydrogen will have a partial positive charge
19.Provide an example of how covalent bonding holds molecules together -
ANSWER Hydrogen atoms only have 1 electron, so it is unstable and does
not have a full valence shell. (Hydrogen atoms need two electrons in order
for it to have a full valence shell/be stable) So, instead two hydrogen atoms
can share their electrons so that they can both be stable.
, 20.Ionic bonds - ANSWER the transfer of electrons between two atoms
21.ions - ANSWER an atom or molecule that carries a full charge rather than
the partial charge that arises from polar covalent bonds
22.What happens when an element loses an electron? - ANSWER have a
positive charge (+1)
23.What happens when an element gains an electron? - ANSWER Have a
negative charge (-)
24.cation - ANSWER a positively charged ion
25.anion - ANSWER a negatively charged ion
26.What happens to molecules in water? - ANSWER - polar molecules
dissolve in water (hydrophilic)
- non polar molecules stick to each other (hydrophobic)
27.Bases - ANSWER substances that acquire protons during chemical
reactions and lower the hydronium ion [water]
- adding a base to a solution lowers the [protons]
28.What can be found in all amino acids - ANSWER a central carbon atom
bonds covalently to the four different atoms or groups of atom:
Questions with 100% Correct Answers
Already Graded A+
1. Protons - ANSWER - have a positive charge
- Number of protons cannot vary so if it were to change then the
element itself is different and will be longer be the same.
the number of neutrons can change, and it will remain the same element.
These are known as isotopes
2. neutrons - ANSWER - have a negative charge
3. Isotope - ANSWER when he number of neutrons charges but the element
remains the same
4. Hydrophilic - ANSWER when a solute dissolved in water ("water loving")
- Polar molecules
5. Hydrophobic - ANSWER substances that do not interact with/ dissolve in
water ("water fearing")
- Nonpolar molecules
6. What properties are correlated with water's structure - ANSWER - cohesion
- adhesion.
- surface tension
,7. Cohesion - ANSWER attraction between like molecules
- water molecules
8. adhesion - ANSWER attraction between unlike molecules
- interaction between water and a solid surface
9. surface tension - ANSWER is the cohesive force caused by attraction
between the molecules at the surface of a liquid
- any force that depresses a water's surface meets with resistance and so
it makes water's surface act like an elastic membrane
10.Electronegativity - ANSWER when atoms of different elements form a
bond by pulling the shared electrons towards their nuclei with varying
strengths.
- From most to least electronegative element: O > N > S ≈ C ≈ H ≈ P
11.What is responsible for an atom's electronegativity? - ANSWER - The
number of protons in the nucleus and the distance between the nucleus and
the valence shell.
12.Oxygen - ANSWER attracts covalently bonded electrons more strongly
than any other atom commonly found in organisms.
,13.Chemical equilibrium - ANSWER when forward and reverse reactions
proceed at the same rate
14.Acids - ANSWER substances that give up protons during chemical
reactions and raise the hydronium ion [water]
- adding an acid to a solution increases the [protons]
15.Covalent bond - ANSWER a strong attraction where two atoms share
electrons (nonmetal and nonmetal)
16.Nonpolar covalent bond - ANSWER a bond that involves equal shared
electrons
17.Polar covalent bond - ANSWER asymmetric sharing of electrons
18.Why is it important to know why electrons in a polar covalent bond spend
most of their time close to the nucleus of the more electronegative atom? -
ANSWER In a water molecule the electrons are not shared equally but are
held tightly by the oxygens nucleus than the hydrogens nucleus.
- Due to the unequal sharing of electrons oxygen will have a partial
negative charge and hydrogen will have a partial positive charge
19.Provide an example of how covalent bonding holds molecules together -
ANSWER Hydrogen atoms only have 1 electron, so it is unstable and does
not have a full valence shell. (Hydrogen atoms need two electrons in order
for it to have a full valence shell/be stable) So, instead two hydrogen atoms
can share their electrons so that they can both be stable.
, 20.Ionic bonds - ANSWER the transfer of electrons between two atoms
21.ions - ANSWER an atom or molecule that carries a full charge rather than
the partial charge that arises from polar covalent bonds
22.What happens when an element loses an electron? - ANSWER have a
positive charge (+1)
23.What happens when an element gains an electron? - ANSWER Have a
negative charge (-)
24.cation - ANSWER a positively charged ion
25.anion - ANSWER a negatively charged ion
26.What happens to molecules in water? - ANSWER - polar molecules
dissolve in water (hydrophilic)
- non polar molecules stick to each other (hydrophobic)
27.Bases - ANSWER substances that acquire protons during chemical
reactions and lower the hydronium ion [water]
- adding a base to a solution lowers the [protons]
28.What can be found in all amino acids - ANSWER a central carbon atom
bonds covalently to the four different atoms or groups of atom:
