AICE Marine Science Unit 1

Particle Theory

Particle Theory

Matter is made of particles that are in constant motion based on the amount of energy they have

more dense water less dense water

sinks rises

covalent bond

when 2 atoms share a pair of electrons (in their outer shell) (strongest bonds)

ionic bond

bond where there is an attraction between 2 oppositely charged ions

covalent bond

when two atoms share a pair of electrons (in their outer shell) (strongest bond)

hydrogen bond

a relatively weak bond formed between molecules containing a hydrogen atom bonded to an oxygen, nitrogen, or fluorine atom

sodium chloride

NaCl

calcium carbonate

CaCO3

magnesium sulfate

MgSO4

Chemical composition of water

Local changes occur due to:

1. Volcanic Activity

2. runoff

3. atmospheric dissolution

what causes mixing in the ocean?

1. strong wind/wave action (storms)

2. currents

3. upwellings

4. cold surface water sinking

What makes density of water

· Water is less dense as a solid than it is as a liquid · This happens because the hydrogen bonds in ice are stable and at a fixed distance, keeping the water molecules further apart.

Explain how temperature gradients form

1. Differences in salinity

2. Warm water above cold water

3. lower salinity above higher salinity

4. do not mix

why Oxygen is less soluble than in freshwater?

explanation: higher salinities (so higher TDS) in water leaves less space for gases to "fit" into

Precipitation

1. dilutes sea water, decreases salinity

2. places especially affected: estuaries and near glaciers

Particle Theory

Matter is made up of tiny particles which are constantly moving.

covalent bond

A chemical bond that involves sharing a pair of electrons in their outer shell

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

Evaporation

salt stays in solution, salinity increases

What affects salinity?

1. wind, but only from surface to ~200m deep

2. Currents

3. Temperature changes

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Density

1. As salinity increases, density increases

2. Lower salinity (and lower density) water on top of higher salinity (and higher density) water

As temperature increases

density decreases

atmospheric pressure

more oxygen will dissolve when pressure is increased -oxygen in atmosphere is "forced" into ocean by pressure

water pressure

the greater the depth of water the greater the pressure which causes increases oxygen dissolution

• pressure "forces" oxygen into the water

As depth increases...

DO decreases

DO can become saturated when

1. photosynthesis

2. turbulence caused by waves

3. most DO at the surface

DO can decrease by

1. respiration

2. increase in temperature

vampire squid

threatened by decreasing oxygen doesnt move due to little oxygen

Jubillee

upwelling of oxygen-poor bottom waters force fish from deep water of mobile bay to shallower coaster areas

salinity increases

density increases

Warm and cold water don't mix well. Why?

1. forms temperature gradients

2. warm water sits on top of cold water

Dissolved Oxygen (explain)

1. high concentration at the surface layer due to turbulence and photosynthesis

2. extremely low concentration below the surface layer due to respiration but lack of turbulence and photosynthesis (no light)

3. increase in deeper water due to few organisms respirating but increases dissolution as a result of high pressure and cold water

Dissolved Oxygen (describe)

1. high concentration of DO at the surface

2. Then it decreases rapidly as depth increases

3. Then it increases rapidly as depth increases before becoming constant

cold water can dissolve more oxygen than warm water. Why?

explanation: warmer water has more (kinetic) energy and the molecules move faster which causes molecules to evaporate quickly

atmospheric dissolution

• dissolved gases remain at equilibrium (mostly) with atmosphere

• concentrations depend on relative solubility, temperature, pressure, and salinity of the ocean

runoff

-flow of water from land to ocean

• drains to oceans directly from rivers

volcanic activity

-Submerged volcanoes release gases, including chlorine

• major source of chloride ions

• dissolve in atmospheric h2o -enter ocean by precipitation

Volcanic activity gases

CO2, SO2, H2S, HCI

Hydrogen bonds and water

in water, oxygen atom has a negative charge, hydrogen atoms have a positive charge

Designing an experiment

1. determine the IV and range of values

2. Determine the control variables

3. Determine how to keep control variables the same

4. Decide on the number of replicates

5. Determine the timeframe

6. Determine the measurements that will be taken