Polarity, Biochem Basics, Stats

A covalent bond with an unequal sharing of electrons is:

• ionic
• polar
• non-polar
• isometric

The smallest basic unit of matter is the

• molecule.
• atom.
• compound.
• cell.

Tags

NGSS.HS-PS1-7

Atoms in molecules share pairs of electrons when they form

• covalent bonds.

• ionic bonds.

• hydrogen bonds.

• polymers.

Tags

NGSS.HS-PS1-1

The positively charged particle in the nucleus of an atom is called the

• neutron

• ion

• proton

• electron

Which is considered neutral?

• pH of 4
• pH of 9
• pH of 14
• pH of 7

Tomato juice has a pH of 4. Determine if it's an acid, base, or neutral. 

• acid
• base
• neutral 

Household bleach has a pH of 12. Determine if it's an acid, base, or neutral.

• acid
• base
• neutral 

Attractions between the (partial) negative Oxygen atom of one water molecule and the (partial) positive Hydrogen atom of another water molecule are called

• Covalent bonds
• Ionic bonds
• Polar bonds
• Hydrogen bonds

Which end of the water molecule has a slightly positive charge?

• the oxygen end
• the hydrogen end
• both ends are slightly positive
• neither end is positive

 Small insects can walk across the surface of calm water. Their feet push the surface of the water down slightly, somewhat like a person walking across a trampoline, but they do not break the surface. What is the best explanation for why this happens?

• The insects are light enough so that they do not break the hydrogen bonds holding the water molecules together
• The insects actually use their wings to hover slightly above the water's surface and they only skim it with their feet
• The insects' feet are non-polar, so they are repelled by the polar water molecules and are pushed away from the water's surface
• The insects are small enough to see the individual water molecules, so they are able to step carefully from one molecule to the next