Atoms, Molecules, and Water Flashcards
What is Matter?
Anything that contains mass
What are Molecules?
Two or more atoms bonded together
What are p-orbitals shaped like?
Dumbbells
What is the atomic number?
Number of protons in an atom
How do you calculate Atomic Mass?
Add the number of Protons to the number of Neutrons
A Carbon atom has 6 Protons and 6 Neutrons. What is it’s atomic mass?
12 Daltons
Atomic mass is measured in what unit?
Daltons
What are Trace Elements?
Elements that are present in organisms in small amounts but are essential for normal growth and function
What are Compounds?
Molecules composed of two or more different elenents
What are Covalent Bonds?
Chemical bond which two atoms share 1 pair of electrons
What is the Octet Rule?
The rule states that atoms are most stable when they have 8 electrons in the outermost electron shell
What are Double Bonds?
When atoms share 2 pairs of electrons
What is Electronegativity of an atom?
It’s measurement of it’s ability to attract electrons in a bond with another atom.
Note: When two atoms with different electronegativities form a covalent bond, the shared electrons are more likely to be closer to the nucleus of the atom of higher electronegativity
TRUE or FALSE
Water is considered a Polar Covalent Bond?
TRUE
Note: Because Oxygen is much more electronegative than Hydrogen, the shared electrons tend to be pulled closer to the Oxygen nucleus
How does an atom or molecule become a Ion?
If it gains or loses one or more electrons, it will acquire a net electric charge and become an Ion.
Note: If the Ion have a net positive charge, it is called a Cation. If it has a net negative charge, it is called Anions
What is a Free Radical?
A molecule containing an atom with a single, unpaired electron in its outer shell
What is a Catalyst?
An agent that speeds up the rate of a chemical reaction
What is Molecular Mass?
The sum of the atomic masses of all the atoms in the molecule.
For example; Glucose
(C6 H12 O6) has a molecular mass of 180
What is a Hydrogen Bond?
A weak interaction between hydrogen atom and a electronegative atom such as oxygen or nitrogen
Why is water a solvent for most chemical reactions in all living organisms?
Atoms and molecules dissolved in water interact in ways that wouldn’t be possible in their undissolved states
The pH of a solution is the :______________________
Negative logarithm to the base 10 of the H+ concentration
What is the pH of pure water?
7 neutral
What is a buffer?
A pair of substances, an acid and its related base and it minimizes pH fluctuations
What are the three states of matter?
Solid, Liquid and Gas
