Biology Quiz 2

atom

What is the smallest unit of an element?

how many protons the element has

What does the atomic number tell you about the element?

how many protons and neutrons the element has

What does the atomic mass tell you about the element?

an element with the same number of protons but a different number of neutrons

What is an isotope?

An isotope with an unstable nucleus

What is a radioactive isotope?

positive (+)
located in nucleus

What is the charge of a proton? Where is it located?

neutral (no charge)
located in nucleus

What is the charge of a neutron? Where is it located?

negative (-)
located outside of nucleus, electron shell

What is the charge of an electron? Where is it located?

2, 8, 8

How many electrons can be held in each of the first three shells of an atom?

gaining or losing an electron

What makes an atom an ion?

covalent bond

What kind of chemical bond holds the atoms together within a water molecule?

polar

Is water polar or non-polar?

hydrogen bond

What kind of non-chemical bond holds one molecule of water to another molecule of water?

covalent, ionic, hydrogen

What are the three types of bonds?

shares electrons with other atoms

What is a covalent bond?

the attraction between oppositely charged ions

What is an ionic bond?

attraction between a covalently bonded hydrogen atom and another atom taking part in a separate polar covalent bond

What is a hydrogen bond?

hydrogen bond

What type of bond occurs when water molecules hold each other?

ionic bond

What type of bond holds the ions Na+ to Cl- (to form NaCl)?

covalent bond

What bond connects atoms that share electrons?

carbon

Organic molecules are complex molecules of life, built on a framework of _____________ atoms

Cells use water to cause polymers to split into monomers. As a result, an enzyme attaches to a hydroxyl group and a hydrogen atom.

Describe what happens during a hydrolysis reaction. What is the result?

Monomers are built into polymers. This reaction forms water.

Describe what happens during a condensation reaction. What is the result?

Matter is any substance that occupies a space and has a mass.

What is matter?

Elements are unique forms of matter with specific chemical and physical properties that cannot be broken down into smaller substances by ordinary chemical reactions.

What are elements?

oxygen (o)
carbon (c)
hydrogen (h)
nitrogen (n)

What are the 4 elements common to all living things?

2 or more atoms chemically bonded together

What is a molecule?

The outermost electron shell. It determines stability of an atom and its tendency to form chemical bonds.

What is the valence shell?

It becomes a different element.

What happens if you change the number of protons of an atom?

It becomes an isotope.

What happens if you change the number of neutrons of an atom?

It becomes an ion.

What happens if you change the number of electrons in an atom?

substances at the beginning of a chemical equation (left side)

What are reactants?

substances found at the end of a reaction (right side)

What are products?

reactions that can go in either direction

What are reversible reactions?

The ability of some elements to attract electrons, acquiring partial negative charges in molecules and creating partial positive charges on hydrogen atoms (desire or lack of that an atom has for electrons).

What is electronegativity?

water loving

Define hydrophillic.

water fearing

Define hydrophobic

The attraction of water molecules to each other.

Define cohesion.

The attraction of water molecules to other molecules.

Define adhesion.

to neutralize

What is the purpose of buffers?

It can form covalent bonds with itself and other elements.

Why is carbon so versatile?

anything living or once living

What is an organic molecule?