Water origin (1)

What is hard water made from

What is hard water made from

Deuterium

What is deuterium

Isotope of hydrogen used in nuclear plants

How is the hydrogen bond formed

dipole-dipole

Why does ice have a higher volume

Crystal structure, hexagonal ice

By how much does ice volume increase

9%

What and how many forms of ice are there?

19 forms in total, 16 crystalline and 3 amorphous

How is the density of ice compared to liquid water

ice has lower density

What temperature is maximum density at

4 degrees

Why are circulation periods important

Circulation of compounds and biotic part of ecosystem

Epilimnion

Top layer of water in the summer, holding circulation. Photosynthesis

Metalimnion or thermocline

stagnation layer, water does not move here in the summer, most O2 concentration here

Hypolimnion

Bottom layer of water in the summer, holds circulation in opposite direction than the epilimnion. Respiration and decomposition

What happens in the autumn and spring with the water in a lake?

Overturn - happens when the top layer cools down to the temperature of the layers below

What happens in winter with the layers in a lake?

The top layer is ice, right below the water is around 0 degrees and 4 degrees tp the bottom. At the very bottom there is very little effective circulation.

Amicitic lake

Ice covered year-round

Cold monomictic

Water temperature never exceed 4 degrees, one circulation period in summer

Dimictic

Circulation in spring and autumn, stagnation in summer and stratification in winter

Warm monomictic

Not ice covered, one free circulation in winter at 4 degrees and stratified for the rest of the year

Oligomictic

Stratified much of the year but cool sometimes to circulate - irregularly, no ice

Polymictic

Frequent periods of circulation, no ice

Name the types of lakes

Amicitic, Cold monomictic, Dimictic, Warm monomictic, Oligomictic, Polymictic

What type of molecules does water dissolve?

Polar molecules

What is water solubility dependent on

Mineralisation of inorganic and organic substances

Mpemba effect

Hot water can freeze sooner than cold water