BIOL 220 Second quiz

Question 1

Chemistry can be broken down into (What two branches?)

Answer 1

Basic chemistry
Biochemistry

Question 2

Matter (definition)

Answer 2

Matter is anything that has mass and occupies space
- Matter can be seen, smelled, and/or felt
- Weight is mass plus the effects of gravity

Question 3

How many states can matter exist in?

Answer 3

3 states

Question 4

Energy (definition)

Answer 4

Energy is the capacity to do work or put matter into motion

Question 5

4 forms of energy (what are they?)

Answer 5

4 Forms of energy
- Chemical energy
- Mechanical energy
- Electrical energy
- Radiant/electromagnetic energy

Question 6

Elements (definition)

Answer 6

Elements are substances that cannot be broken down into simpler substances by ordinary chemical methods

Question 7

4 elements make up what percent of the body?

Answer 7

Four elements make up 96% of body: 24 in total
- Carbon, oxygen, hydrogen, and nitrogen

Question 8

What do atoms do?

Answer 8

• give each element its particular physical & chemical properties
• make up everything we know

Question 9

Protons (characteristics)

Answer 9

Protons
- Carry a positive charge
- Weigh an arbitrary 1 atomic mass unit (1 amu)

Question 10

Neutrons (characteristics)

Answer 10

Neutrons
- Have no electrical charge
- Also weigh 1 amu

Question 11

Electrons (characteristics)

Answer 11

Electrons
- Carry a negative charge
- Are so tiny they have virtually no weight (0 amu)

Question 12

Where are protons and electrons found?

Answer 12

Protons and neutrons are found in a centrally located nucleus; electrons orbit around the nucleus

Question 13

What are the two models that represent atoms?

Answer 13

• Planetary model (outdated): circle around nucleus
• Orbital model (modern): foggy around nucleus

Question 14

Atomic number (shows what?)

Answer 14

Atomic number = number of protons
Number of protons in nucleus

Question 15

Mass number (shows what?)

Answer 15

Mass number = total of protons and electrons
- Total number of protons and electrons in nucleus
- Total mass of atom

Question 16

Isotopes (what are they?)

Answer 16

Isotopes
- Structural variations of same element
- Atoms contain same number of protons but differ in the number of neutrons they contain

Question 17

Atomic weight (Definition)

Answer 17

Atomic weight
Average of mass numbers of all isotope forms of an atom

Question 18

Radioisotopes (what are they?)

Answer 18

Radioisotopes are isotopes that decompose to more stable forms
(they can sometimes become different elements) (this is where half lives come in)

Question 19

Molecule (definition)

Answer 19

Molecule: general term for 2 or more atoms bonded together

Question 20

Compound (definition)

Answer 20

Compound: specific molecule that has 2 or more different kinds of atoms bonded together

Question 23

3 Types of mixtures (Solutions)

Answer 23

Solutions: solute particles are very tiny, do not setle out or scatter through (water)

Question 24

3 Types of mixtures (Colloids)

Answer 24

Colloids: solute particles are larger than in a solution and scatter light; do not settle out
- Some undergo sol-gel (solution to gel) transformations

Question 25

3 Types of mixtures (Suspensions)

Answer 25

Suspensions: solute particles are very large and settle out and may scatter light

Question 26

Solvent (definition)

Answer 26

Solvent: substance present in greatest amount - Usually a liquid, such as water

Question 27

Solute (definition)

Answer 27

Solute(s): substance dissolved in solvent - Present in smaller amounts - Example: blood sugar – glucose is solute, and blood (plasma) is solvent

Question 28

3 Differences between mixtures and compounds

Answer 28

- Mixtures do not involve chemical bonding between components - Mixtures can be separated by physical means, such as straining or filtering - Mixtures can be heterogeneous or homogeneous; compounds are only homogeneous

Question 29

Electron shells (What does each level hold?)

Answer 29

Shell 1 can hold only 2 electrons Shell 2 holds a maximum of 8 electrons Shell 3 holds a maximum of 18 electrons

Question 30

Valance electrons (What are they?)

Answer 30

- Electrons in valence shell have the most potential energy because they are farthest from nucleus - These are electrons that are involved in chemical reactions - They are the only ones that react in chemical bonding