Review for Unix 1 : En Rimed Revine of Bining (15)

Flashcards about the basics of matter, energy, atoms, and chemical bonds.

What are the two components that the universe is made out of?

Energy and matter.

What is the significance of the amount of energy and matter in the Universe?

The total amount of energy and matter in the Universe is constant.

What is the estimated age of the Big Bang?

13.7 billion years ago.

What happens to the volume of space and the amount of energy/matter in the universe?

The volume of space is expanding, but the amount of energy and matter never changes.

List examples of consequences of the Universe expansion

Diffusion and living systems taking advantage of Universe extension.

List the four fundamental forces of matter, from strongest to weakest.

Strong nuclear interaction, electromagnetic interaction, weak nuclear interaction, gravity.

Which fundamental interaction is intrinsic for living systems?

Electromagnetic interaction.

What is the relationship between energy and binding/separation of matter?

Energy separates matter; without energy matter will bind.

What determines the likelihood of separation in an object?

The greater amount of energy that the matter of an object has, the higher the chance of separation.

What are the three subatomic particles?

Proton, neutron, and electron.

What is atomic number?

Each element has a unique atomic number, which provides the number of protons in the nucleus.

What is atomic mass?

It's approximately the number of protons and neutrons in the nucleus.

What is a covalent bond?

The sharing of a pair of electrons between two atoms.

What happens to energy when covalent bonds are formed and broken?

When covalent bonds are formed, energy is released; to break covalent bonds, energy must be added.

What is a compound?

A molecule made of more than one atom.

What is an organic compound?

Any molecule that has a C-C bond or at least a C-H bond.

What is the function of electrons regarding energy in living systems?

Electrons carry energy used by living systems, and wherever electrons go, energy follows.

What is an orbital and what are its characteristics?

Orbital is the volume of space around a nucleus in which electrons are most likely to be found; it can hold 0-2 electrons, has different shapes and spatial orientations.

List the elements most disclosed in living systems.

Hydrogen, carbon, nitrogen, oxygen, phosphorus, and sulfur.

What is the relationship between atomic orbitals and covalent bonds?

Covalent bonds of molecules are formed within the same volumes that atomic orbitals occupy.

What are lone pairs?

Lone pairs are volumes of strong negative charge.

What is electronegativity?

A measurement of the strength with which a nucleus attracts electrons.

What situation create partial negative and partial positive charges?

Unequal sharing of electrons in a covalent bond.

Describe the electronegativity difference formula and its values.

Formula |XA - XB|; 0-0.4 = Pure (nonpolar) Covalent Bond; 0.4-2.0 = Polar covalent Bond; 2.0-4.0 = Ionic Bond.

What does it mean if a molecule is hydrophilic?

A molecule that can dissolve in water because it has charged atoms and/or Polar Bonds.

What does it mean if a molecule is hydrophobic?

A molecule that cannot dissolve in water because it lacks charged atoms and/or Polar Bonds.

What is an ion?

An atom that has gained or lost at least 1 electron.

What is a cation?

An atom with fewer electrons than protons, resulting in a positive charge.

What is an anion?

An atom with more electrons than protons, resulting in a negative charge.

Define ionic bond

An electrical attraction between ions of opposite charges.

What is a hydrogen bond?

A weak electrical attraction between a hydrogen atom with a partial positive charge and another atom with a partial negative charge.

List the bonds in order of strength.

Covalent Bond, Ionic Bond, Hydrogen Bond, Hydrophobic Interaction.

What is the hydrophobic effect?

Energetically favorable association of nonpolar surfaces in aqueous solutions.

The teaching that 'an atom cannot provide both of the electrons in a covalent bond with another atom'

Not True.