IB Biology HL A1.1 MC

Solvent

• The layer of water molecules at the surface has a relatively strong cohesion force around and below the water molecules allowing it to act like a solid. 

• Substance that dissolves a solute

• The epidermal cells of leaves are capable of secreting a wax that is used to coat the leaves to prevent excessive water loss.

• Upward force exerted on an object placed in the medium – either water or air

Polar covalent bond

• Forms when two atoms share electrons unequally

• An attraction between two unlike molecules due to hydrogen bonding.

• The amount of heat that must be added to one gram of a substance in order to raise its temperature by one degree celsius

• Attracted to water. Any substance that dissolves readily in water, ex. polar substances 

Tags

NGSS.HS-PS2-6

Non-polar covalent bonds

• Substance that dissolves a solute

• Not attracted to water. Any substance that does not dissolve easily in water, ex. nonpolar substances

• A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other

• Form when two atoms equally share electrons because neither of the atoms has a higher density of electrons than another

Hydrogen bonds

• The small tubes in a plant that moves the water upwards

• Form when two atoms equally share electrons because neither of the atoms has a higher density of electrons than another

• A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other

• A measure of the ability of a material to transfer heat

Cohesion

• Occurs when molecules of the same type are attracted to each other. (Water has cohesive properties)

• Not attracted to water. Any substance that does not dissolve easily in water, ex. nonpolar substances

• Upward force exerted on an object placed in the medium – either water or air

• Not attracted to water. Any substance that does not dissolve easily in water, ex. nonpolar substances

Tags

NGSS.MS-ESS2-4

Surface tension

• Attracted to water. Any substance that dissolves readily in water, ex. polar substances 

• Force that pulls on the water molecules upwards towards leafs due to evaporation of water through stomata. 

• Forms when two atoms share electrons unequally

• The layer of water molecules at the surface has a relatively strong cohesion force around and below the water molecules allowing it to act like a solid. 

Tags

NGSS.MS-ESS2-4

Xylem

• The amount of heat that must be added to one gram of a substance in order to raise its temperature by one degree celsius

• The small tubes in a plant that moves the water upwards

• Resistance of a fluid (liquid or gas) to a change in shape or movement of neighboring portions relative to one another; opposition to flow.

• Attracted to water. Any substance that dissolves readily in water, ex. polar substances 

Tags

NGSS.MS-ESS2-4

NGSS.MS-LS2-3

Negative pressure

• An attraction between two unlike molecules due to hydrogen bonding

• Substance that dissolves a solute

• Force that pulls on the water molecules upwards towards leafs due to evaporation of water through stomata. 

• Form when two atoms equally share electrons because neither of the atoms has a higher density of electrons than another

Tags

NGSS.MS-PS2-5

Adhesion

• The epidermal cells of leaves are capable of secreting a wax that is used to coat the leaves to prevent excessive water loss.

• The layer of water molecules at the surface has a relatively strong cohesion force around and below the water molecules allowing it to act like a solid. 

• An attraction between two unlike molecules due to hydrogen bonding.

• A measure of the ability of a material to transfer heat

Aqueous solution

• Any solution that has water as the solvent.

• Substance that dissolves a solute

• A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other

• Upward force exerted on an object placed in the medium – either water or air

Tags

NGSS.MS-ESS2-4