Chemical Bonds and Water Properties - Flashcards

Flashcards covering key concepts from the lecture notes on chemical bonds (covalent, ionic, hydrogen), polarity, and pH, including carbon's bonding versatility and water's properties.

What is an element?

A basic substance that cannot be broken down by chemical means; composed of one type of atom.

What is an atom?

The basic unit of a chemical element, containing a nucleus with protons (and neutrons) and electrons surrounding it.

What are protons?

Positively charged subatomic particles located in the nucleus.

What are electrons?

Negatively charged subatomic particles that orbit the nucleus and determine an atom's charge.

What is a chemical bond?

A force that holds atoms together, enabling interactions between atoms.

What is a molecule?

A group of two or more atoms held together by covalent bonds.

What is an ion?

An atom or molecule with a net electric charge due to gain or loss of electrons.

What are valence electrons?

Electrons in the outermost shell involved in bonding.

What is the octet rule?

Most atoms tend to fill their valence shell to eight electrons; hydrogen and helium are exceptions and fill their shells with two.

What does electronegative mean?

Having a strong tendency to attract electrons in a chemical bond.

What is a covalent bond?

A bond formed when atoms share electrons.

What is an ionic bond?

An electrostatic bond formed by the attraction between oppositely charged ions, usually after transfer of electrons.

What is a hydrogen bond?

A weak bond between a hydrogen atom in one molecule and an electronegative atom in another (or within the same molecule).

What does hydrophilic mean?

Loves water; interacts with water or dissolves in water.

What does hydrophobic mean?

Fears water; nonpolar substances that repel water.

What is pH?

A measure of the hydrogen ion concentration in a solution; pH = -log[H+].

What is an acid?

A substance that increases the hydrogen ion concentration in a solution.

What is a base?

A substance that decreases H+ concentration (or increases OH-).

How many protons does carbon have?

6.

How many protons does hydrogen have?

1.

How many protons does oxygen have?

8.

How many valence electrons does hydrogen have?

1.

How many more electrons does hydrogen need to fill its valence shell?

1.

In a hydrogen-hydrogen bond, how many electrons are in each hydrogen's outer shell after bonding?

Two electrons are in each hydrogen's outer shell (the two electrons are shared, giving each H a full valence shell).

How many valence electrons does carbon have?

4.

How many more electrons does carbon need to fill its valence shell?

4.

How many electrons are shared in a carbon-oxygen double bond?

Four electrons are shared (two electron pairs) in a C=O double bond.

Why can carbon form four covalent bonds?

Because carbon has four valence electrons, allowing it to form up to four covalent bonds to reach an octet.

What is the octet rule used for predicting bonding?

Guides predicting that atoms tend to fill their valence shells to eight electrons (with H/He filling two).

In water, which atom is more electronegative?

Oxygen is more electronegative than hydrogen, causing polar covalent bonds.