Chapter 2 The nature of Molecules and Properties of Water

What is the charge of a proton?

positive

What is the charge of a neutron?

no charge

What is the charge of an electron?

negative

The number of electrons is equal to the number of....?

Protons

C is the ________ for carbon.

symbol

6 is the _______ _______ of carbon.

atomic number

12.01 is the _______ _____ of carbon.

Atomic weight

The equation to calculate the atomic mass is

# of protons + # of neutrons

The equation to calculate the number of neutrons is

atomic weight - atomic number

silver (Ag), atomic weight 107, atomic # of 47... What is the number of protons?

47 protons

silver (Ag), atomic weight 107, atomic # of 47... What is the number of electrons?

47 electrons

silver (Ag), atomic weight 107, atomic # of 47... What is the number of neutrons?

60 neutrons (107 - 47)

The number of protons is equal to the number of .....?

Electrons

What is it called when atoms have the same number of protons and electrons but a different number of neutrons?

Isotopes

Isotopes facts

- can be unstable

- nucleus breaks apart

- radioactive

What is carbon dating?

Of the three subatomic particles only ________ are directly involved in chemical activity of an atom.

Electrons

Electrons have different _______ _____ such as K,L,M,N

energy levels (shells)

Electrons from the nucleus have more or less energy?

More

Energy levels indicate

the amount of energy that an electron has.

The number of electrons in the outermost shell, called the _______ ______, determines the chemical properties of the atom.

valence shell

Atoms whose valence shells are not full (have unpaired electrons) tend to interact with other atoms participating in chemical reactions.

Electrons orbit around the nucleus in ______ such as s,p,d,f.

orbitals

no orbital can contain more than __ electrons.

2

Look into electron orbitals

Study electron orbitals

When electrons absorb light energy (photons) they....

move to a higher energy level.

When electrons lose or emit energy (heat or light) they.....

move closer to the nucleus

_____ form when an atom gains or loses electrons.

Ions

What is a positively charges ion resulting from the loss of electrons?

Cations

What is a negatively charged ion resulting from the gain of electrons?

Anions

Aluminum +3 (Al3+) with atomic number of 13 has how many electrons?

10

Oxidation

compound A loses electrons

Reduction

Compound B gains electrons

Atoms with incomplete outer shells tend to react so both atoms end up with completed outer shells.

What are atoms made of?

protons, neutrons, electrons

Chemical bonds may react with each other by _____,_____, or ______ electrons.

sharing, donating, or receiving

Covalent bond

- sharing of electron pairs

- strong

Ionic bond

-Attraction of opposite charges

-Strong

Hydrogen bond

-Sharing of H atom

- Weak

Hydrophobic interactions

-Forcing of hydrophobic portions of molecules together in presence of polar substances

-weaker

Van der Waals attraction

-Weak attractions between atoms due to oppositely polarized electron clouds

what is formed between two oppositely charged ions (cations and anions)?

ionic bonds

What is it called when two atoms share one or more pairs of outer- shell electrons?

covalent bonds

Single covalent bond

H-H

Double covalent bond

O=O

Nonpolar Covalent bond

C-C

what is the atoms attraction (pull) for shared electrons

electronegativity

Polar covalent bond

O-H

What forms between hydrogen atoms and one molecule and an electronegative atom (O,N,F) of another molecule

Hydrogen bonds

The formation and breaking of chemical bonds

Chemical reactions

The rate of the chemical reaction depends on what three factors?

-catalysts

-temperature

-concentrations of reactant vs products

Products is on the right of left of the reaction?

right

Reactants are on the right of left of the reaction?

left

H2O is

cohesive and adhesive

______ is when H2O molecules stick to other H2O molecules by hydrogen bonding.

- In relation to surface tension

-cohesion

______ is when H2O molecules stick to other polar molecules by hydrogen bonding.

- in relation to capillary action

adhesion

Cohesive and adhesive properties of water work together to move water from the roots to the leaves of plants.

H20 is a high specific heat which means

a large amount of heat (energy) is needed to raise the temperature of water.

H2O has a high heat of vaporization which means

-a lot of heat (energy) is necessary to turn liquid water into vapor.

-allows living things to release excess body heat via sweating.

Frozen H2O (ice) is more or less dense than liquid H2O?

less dense

Bodies of water freeze from the top down

H2O is a universal solvent it dissolves polar molecules and ions (solutes)

hydrophilic means

water loving

hydrophobic means

water fearing

pH equation =

-log [H+]

A substance that minimizes changes in pH is?

A buffer

A buffer donates H+ when the solution becomes too

basic

A buffer accepts H+ when the solution becomes too

acidic

Atoms are made of?

Protons, neutrons, and electrons

What is the difference between the atomic number and atomic mass?

-Atomic mass is the same as atomic weight

-Atomic number is the amount of protons present

Acidosis

-excess acid in the body

-can disrupt bodies acid base levels

-can cause health issues

Alkalosis

-excess base (alkali) in the body

-elevated blood pH.

What causes blood acidosis vs alkalosis?

Acidosis: blood becomes too acidic/blood pH drops below 7.35 (hypoventilation)

Alkalosis: blood becomes to basic/blood pH rises above 7.45 (hyperventilation)

What is the difference between oxidation and reduction?

Oxidation involves loss of electrons.

Reduction involves gain of electrons.

remember LEO says GER

-LEO- Lose Electrons - Oxidation

-GER- Gain Electrons- Reduction

What is the difference between electron energy levels and orbitals?

Energy levels indicate the amount of energy that an electron has, but orbitals are where electrons are most likely located around the nucleus.

What is the difference between polar and non polar covalent bonds?

Polar covalent bonds involve unequal sharing of electrons (example: O-H) while non-polar covalent bonds involve equal sharing. (Example C-C)

How does the specific heat of water help our cells?

The specific heat of water allows our cells to absorb and transfer heat effectively.

How are chemical reactions controlled?

catalysts, temperature, and concentrations of reactants vs. products

What happens to water when it freezes?

it expands and becomes less dense

How do buffers work?

Acts by donating H+ when the pH becomes too basic, and accepts H+ when it becomes too acidic.

What is a hydrophobic exclusion?

Hydrophobic exclusion is when hydrophobic molecules (oil) exclude themselves from H20 instead of being dissolved in it.