Chapter 3 Water and Life Flashcards
Polar molecule
The overall charge of a molecule is unevenly distributed
Ie water; oxygen’s more electromagnetic.
Cohesion
Water held together by hydrogen bonds which contributes to the transport of water and dissolved nutrients against gravity in plants.
Adhesion
The clinging of one substance to another
Surface tension
A measure of how difficult it is to stretch or break the surface of a liquid.
Kinetic energy
The energy of motion
The faster an element moves, the greater its kinetic energy
Heat
A form of energy that measures the matter’s total kinetic energy due to motion of its molecules and therefore is dependent on its volume.
Temperature
A measure of heat intensity that represents the average kinetic energy of the molecules regardless of volume
Calorie
The amount of heat it takes to raise the temperature of 1 gram of water by 1 degree Celsius
Kilocalorie
The quantity of heat required to raise the temperature of 1 kg of water by 1 degree Celsius
1000 calories
Joule
One joule equals .239 calories
1 calorie = 4.184 J
Specific heat
The amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree Celsius
Water’s specific heat is determined by its hydrogen bonds
Heat of vaporization
The quantity of heat a liquid must absorb for 1 g of it to be converted from liquid to the gaseous state.
Polar covalent bond
When the electrons of a covalent bond spend more time on one element
Ie water oxygen is more electronegative than hydrogen so the electrons spend more time near the oxygen.
Heat of vaporization
The quantity of heat a liquid must absorb for 1g of it to be converted from the liquid to the gaseous state.
Evaporative cooling
As liquid a liquid evaporates, the surface of the liquid that remains behind cools down.
Evaporative cooling occurs because the hottest molecules those with the greatest kinetic energy, are the most likely to leave as gas.
