ch.1

Question 1

what is matter defined as

Answer 1

what everything that has mass is made up of

Question 2

how many elements are there

Answer 2

118

Question 3

what is an atom

Answer 3

what each element is made up of

Question 4

what charge do protons carry

Answer 4

positive electrical charge

Question 5

what is the charge of neutrons

Answer 5

no electrical charge

Question 6

what charge do electrons have

Answer 6

negative electrical charge

Question 7

what defines an isotope

Answer 7

atoms that have the same number of protons but different number of neutrons

Question 8

what is a molecule

Answer 8

two or more atoms held together by covalent bonds

Question 9

what is a compound

Answer 9

molecules that are composed of two different elements

Question 10

what are the characteristics of a compound compared to its individual elements

Answer 10

• has characteristics that are different from those of its individual elements
• specific combination of elements
• atoms of elements ate present in specific proportions

Question 11

what happens if the proportions of elements in a compound change

Answer 11

the compound will differ

Question 12

what are the most abundant elements in the human body

Answer 12

Hydrogen, carbon, nitrogen, oxygen, calcium

Question 13

how do isotopes differ from each other

Answer 13

they have a different mass number

Question 14

what is the purpose of identifying isotopes in biology

Answer 14

it is a tool to understand the composition of molecules nad biological processes

Question 15

what determines the behavior of an atom

Answer 15

the number of electrons in the outermost orbital (valence shell)

Question 16

what are chemical bonds

Answer 16

attractive forces between the valency if different atoms and molecules

Question 17

what type of bonds are formed between atoms in a molecule

Answer 17

covalent bonds

Question 18

what type of bonds are formed between molecules

Answer 18

hydrogen bonds

Question 19

what are the two types of strong bonds and their main goal

Answer 19

strong bonds: covalent bonds and ionic bonds
main goals: to fill the outermost shell of electrons (valence electron)

Question 20

how do covalent bonds form

Answer 20

two atoms share one or more pairs of electrons

Question 21

what are common types of covalent bonds

Answer 21

single, double, triple bonds

Question 22

how are ionic bonds formed

Answer 22

through the complete transfer of an electron (s)

Question 23

what is a cation

Answer 23

a positively charged ion

Question 24

what is an anion

Answer 24

a negatively charged ion

Question 25

roles of ions in biology

Answer 25

needed for proper biological functioning in most organisms and are involved in neuronal action potential and muscle contraction

Question 26

how does sodium ion contribute to neuronal action potential

Answer 26

sodium ion channels open, creating an electrical signal that sends information to an axon

Question 27

what role does calcium ion play in muscle contraction

Answer 27

calcium ion creates attractive forces that lead to contraction

Question 28

what is electronegativity

Answer 28

a measure of an atom's attraction for shared electrons in covalent bonds

Question 29

what is the difference between nonpolar and polar covalent bonds

Answer 29

nonpolar covalent bonds share electrons equally while polar covalent bonds have unequal sharing

Question 30

what are lipids characterized by

Answer 30

carbon and hydrogen covalent bonds making them NONPOLAR molecules

Question 31

how do polar covalent bonds affect water molecules

Answer 31

oxygen has a partial negative charge and hydrogen has a partial positive charge

Question 32

what is the relative electronegativity order of abundant elements in bodies

Answer 32

O>N>C~H

Question 33

examples of polar and nonpolar molecules

Answer 33

polar: water nonpolar: lipids

Question 34

what types of bonds can form ions

Answer 34

ionic bonds

Question 35

what are the purposes of weak bonds

Answer 35

allow molecules to interact, adhere when they collide and provide stability within larger molecules

Question 36

what are the three types of weak bonds

Answer 36

1. hydrogen bonding 2. Van der Waals interactions 3. Ionic bonds in water

Question 37

how do hydrogen bonds form

Answer 37

between an atom with a partial negative charge and a hydrogen atom covalently bonded to an electronegative element

Question 38

what are Van der Waals interactions

Answer 38

Interactions between atoms with positively and negatively charged regions

Question 39

why do ionic bonds weaken in water

Answer 39

they are shieled by interactions with water molecules

Question 40

what happens to most drugs that are salts when they are dry compared to in water

Answer 40

they are more stable dry but dissociate well in water