Life of Water Flashcards
What two particles form the atomic nucleus?
Neurons and protons
What is the sharing of valence electrons by two atoms?
Covalent bond
What is the atom’s attraction for electrons in a covalent bond?
Electronegativity
What is true about atoms with high electronegativity?
The more strongly they pull shared electrons toward themselves.
Arrange the atoms in increasing electronegativity.
C, H, O, N
O > N > C ~ H
Compare nonpolar covalent bonds and polar covalent bonds.
In nonpolar covalent bonds, atoms share electrons equally; while in polar covalent bonds, one atom is more electronegative, do not share electrons equally.
What causes partial +ve or -ve charge for each atom of a molecule?
Unequal sharing of electrons or polar covalent bonding
What causes the formation of hydrogen bonds?
When a hydrogen atom that covalently bound to an electronegative atom is also attracted to another electronegative atom.
Is water a polar or non polar molecule? Explain. Why is it important?
Water is a polar molecule due to the high electronegativity of oxygen, which causes the uneven distribution of charges. The polarity allows water molecules to form hydrogen bonds with each other.
What are the properties of water that contribute to suitability for life? (Hint: CAVE)
Cohesive behaviour, Ability to moderate temperature, Versatility as a solvent, Expansion upon freezing
What is cohesion and adhesion?
Cohesion holds together water column and adhesion helps transport water against gravity.
How is heat affected when hydrogen bonds form and break?
Heat is absorbed when hydrogen bonds break and heat is release when hydrogen bonds form.
What is important about the high specific heat of water?
It minimizes temperature fluctutations to within limits that permit life.
Why do ice float?
Ice floats because the hydrogen bonds in ice are more ordered, making ice less dense.
What is true about the hydrogen bonds is ice and liquid water?
Hydrogen bonds in ice are more stable, and hydrogen bonds in liquid water break and re-form.
