General Chemistry and Water Properties

Question 1

What is the atom?

Answer 1

fundamental building blocks of elements

Question 2

What are elements?

Answer 2

all matter in the natural world are composed of one or more substances called elements

Question 3

What is matter?

Answer 3

matter is anything that occupies space and has mass

Question 4

What is a molecule?

Answer 4

combining two or more atoms joined by chemical bonds

Question 5

What is a compound?

Answer 5

a compound is a substance containing at least 2 different elements joined by chemical bonds

Question 6

What are the two types of compounds?

Answer 6

organic and inorganic
organic: have carbon and hydrogen both
inorganic: dont contain both carbon and hydrogen but may have one

Question 7

What is the most abundant element in the human body?

Answer 7

the most abundant element in the body is oxygen: 65%

Question 8

What is atom structure?

Answer 8

a nucleus contains protons and neutrons surrounded by a shell of orbiting electrons

Question 9

electron proton neutron charges?

Answer 9

electron negative charge, proton positive charge, neutron dont have a charge but give mass and weight to the atom

Question 10

What determines which element it is?

Answer 10

the number of protons in the atom determines which element it is

Question 11

What is the top number and bottom number in the periodic table?

Answer 11

the top number: mass number which is the proton and nuetrons
the bottom number: atomic number which is number of protons also the number of electrons

Question 12

How do you calculate the neutrons?

Answer 12

mass number - atomic number

Question 13

What is dalton?

Answer 13

number of protons + number of neutrons

Question 14

How many electrons can each shell hold?

Answer 14

1st shell: 2
2nd shell: 8
3rd shell: 8

Question 15

What is a valence electron?

Answer 15

number of electrons in the outermost shell that are not paired up and balanced.

Question 16

What is the valence electron number for nitrogen? atomic number 7

Answer 16

if the atomic number for nitrogen is 7: the outer shell has 5 which means 3 are unbalanced

Question 17

What are some noble gases?

Answer 17

helium, neon, argon: noble gases have 0 valence electrons and dont have the capacity for chemical reactions

Question 18

Does an atom become more stable when the valence shelled is filled or unfilled?

Answer 18

it becomes more stable when it is filled

Question 19

How do you fill up a valence shell?

Answer 19

chemical bonding which can occur in different ways: covalent and ionic bonding

Question 20

What is covalent bond?

Answer 20

there are two kinds
A: NONPOLAR: electrons are evenly shared between two atoms and the bond is symmetrical
B: POLAR: electrons are asymmetrically shared

Question 21

What is ionic bond?

Answer 21

electrons are transferred from one atom to another

Question 22

What does electronegativity mean?

Answer 22

electronegativity is the tendency of an element to attract electrons. oxygen has very high electronegativity and carbon hydrogen is lower electronegativity

Question 23

What does polarity mean?

Answer 23

distribution of electric charge within a molecule: partial positive and partial negative charge

Question 24

What is a cation vs anion?

Answer 24

cations are positively charged by losing electrons and anions are negatively charged ions by gaining electrons

Question 25

A and B about water?

Answer 25

Water is polar and hydrogen bonds form between water molecules: hydrogen bonds are weak and break easily

Question 26

What are the unique structural properties of water?

Answer 26

1) small size
2) bent shape
3) highly polar covalent bonds
4) overall polarity: assymmetrical distribution

Question 27

Solvent vs Solution vs Solute?

Answer 27

Solution: made by mixing something with water
Solute: substance added to water
Solvent: water
WATER IS A GREAT SOLVENT: THINGS CAN EASILY DISSOLVE

Question 28

Is water more dense in liquid phase than solid phase?

Answer 28

water is denser in liquid phase than solid phase.

Question 29

ice vs liquid?

Answer 29

ice: low temp low kinetic energy
each water molecule has 4 hydrogen bonds and a stable lattice forms
liquid: high temp high kinetic energy
water molecules constantly breaking and forming new hydrogen bonds and no lattice forms

Question 30

Cohesion vs Adhesion?

Answer 30

Cohesion is binding between like molecules and Adhesion is binding between unlike molecules

Question 31

Water and heat sink?

Answer 31

Water has a very high specific heat/heat sink: this means the amount of energy required to raise the temperature of 1 gram of substance by 1 degree celcius

Question 32

Dehydration synthesis vs hydrolysis?

Answer 32

dehydration synthesis builds larger molecules by removing a water molecule but hydrolysis breaks down larger molecules by adding water molecules