Chapter 2: Bio 1

SUEMMMERSSSS

What is an atom?

The smallest unit of an element.

What is a element?

A substance that cannot be broken down chemically.

What is an compound?

Something formed by combining two or parts, elements, or ingredients.

What is an molecule?

the smallest fundamental unit of chemical substances that retains all of its physical and chemical properties.

What is an isotope?

Atoms of an element with a different number of neutrons.

What is an ion?

An atom or molecule with a net electrical charge.

How many elements are meant for life?

17-25

What are the 4 most common elements meant for life?

Carbon, oxygen, nitrogen, hydrogen.

What are the 7 next most common elements?

Sodium, chlorine, magnesium, calcium, potassium, phosphorus, sulfur.

How scarce are the remaining trace elements?

0.01%

Where are neutrons in an atom?

Located in the nucleus of an atom.

Where are protons in an atom?

Also located in the nucleus of an atom.

Where are electrons in an atom?

Located on the outside of an atom.

What is an atomic number?

the exact number of protons in the nucleus of an atom.

What is atomic weight?

the weighted average of the masses of all naturally occurring isotopes of a chemical element

What is molecular weight?

the total mass of a single molecule.

What is mass number?

the total number of protons and neutrons.

What is potential energy?

the stored energy an object or system possesses due to its position, state, or configuration.

What is another name for electron shell?

Energy levels and Electron orbits.

What is valence shell?

the outermost electron shell of an atom.

what are valence electrons?

an electron located in the outermost shell of an atom.

How are covalent bonds be either polar or nonpolar depending on the electronegativities of the bonded atoms?

It determines whether shared electrons are distributed evenly (nonpolar) or pulled closer to one atom (polar).

What are the 2 most common nonpolar covalent bonds?

Carbon-Hydrogen (C-H) bond and the Carbon-Carbon (C-C) bond.

What are the 4 most common polar covalent bonds?

O-H, N-H, C=O, and C-N.

What constitutes a polar nonpolar molecule?

These molecules have an unequal sharing of electrons.

What constitutes a non-polar polar molecule?

These molecules have an equal sharing of electrons.

What are the strong bonds?

Covalent bonds and ionic bonds.

What are the weak bonds?

Hydrogen bonds and Van der waals forces.

What are intermolecular interactions?

They occur within a single molecule.

What are intermolecular interactions?

actions between two or more different molecules.

How many covalent bonds do C usually form?

4 bonds.

How many covalent bonds do H usually form?

1 bond.

How many covalent bonds do O usually form?

2 bonds.

How many covalent bonds do N usually form?

3 bonds.

How does the position of electrons in s and p orbitals differ from the position of electrons in sp3 hybrid orbitals?

s electrons reside in spherical regions centered on the nucleus, while p electrons occupy dumbbell-shaped lobes.

What is a reactant?

A starting material in a chemical reaction.

What is a product?

A substance formed as a result of a chemical reaction.

What is a reversible reaction?

A chemical process where reactants form products, and those products can simultaneously react to revert back into the original reactants.

What is a chemical equilibrium?

The state in a reversible chemical reaction where the forward reaction and the reverse reaction happen at the exact same rate.