Biology: Chapter 2 Flashcards
What are atoms?
Consists of Protons, Nuetrons, and Electrons.
What are ions?
Atoms in which the number of protons does not equal the number of electrons.
What are isotopes?
Atoms in which the number of protons does not equal the number of nuetrons.
What are molecules?
A group of atoms held together by energy. There are four types of bonds that allow this.
What are the four types of bonds?
- Ionic Bonds
- Covalent Bonds
- Hydogren Bonds
- Van Der Waals Force
What are ionic bonds?
What are their key properties?
A chemical bond formed by atoms attracted to each other by opposite electrical charges.
They are strong and not directional.
What are covalent bonds?
What are their key properties?
Covalent bonds are formed when two atoms share electrons.
They hold a very strong chemical bond and they are directional.
What are hydrogen bonds?
What are their key properties?
Hydrogen bonds are when an electropositive hydrogen from one polar molecule is attracted to an electronegative from another polar molecule.
They are weak, and highly directional but they are not effective over long distances.
What is a Van der Waals force?
A Van der Waals force is when there is a weak attraction between two atoms that are close to one another.
What are the five unique properties of water?
- Heat Storage
- Ice Formation
- High Heat of Vaporization
- Cohesion
- Polarity
Explain heat storage.
When hydrogen bonds require considerable heat before they break, minimizing temperature changes.
Explain ice formation.
Water molecules in an ice crystal are placed further apart before of hydrogen bonding.
Explain high heat of vaporization.
Many hydrogen bonds must be broken for water to evaporate.
Explain cohesion.
Hydrogen bonds hold molecules of water together.
Explain high polarity.
Water molecules are attracted to ions and polar compounds.
