Flashcards in Chem Review Deck (60):
The smallest unit of matter that still retains properties of an element.
Three types of subatomic particles?
These two are packed in atomic nucleus.
These occupy outer shells.
Protons have a __ charge
Electrons have a __ charge
Neutrons have a __ charge
Atomic number represents:
Number of protons
Number of electrons in neutral atom
Mass number represents?
Number of Protons + Neutrons
Atomic mass =
Average weight of element (Daltons)
To calculate number of neutrons we:
Mass number - Atomic Number
Two or more atoms held together by a covalent bond = a...
How many electrons in inner most shell?
How many in each shell after?
The outermost shell is called the..
The valence shell contains the...
If an element has a full valence shell they are called...
If the valence shell isn't full...
A sharing of a pair of valence electrons by two atoms is called:
A covalent bond
The bonding capacity of an atom is called it's _____
Valence usually equals...
Number of unpaired electrons needed to complete atom's valence shell.
When two atoms bond by sharing two pairs of valence electrons?
When two atoms bond by sharing only one pair of valence electrons?
The attraction of a particular atom for the electrons of a covalent bond is called:
So, if an atom is more electronegative:
More strongly it pulls shared electrons towards itself.
If two atoms have the same electronegativity they will form a...
Nonpolar covalent bond.
When one atom bonds to a more electronegative atom they will form a...
Polar covalent bond
Which is one of the most highly electronegative?
When two atoms are so unequal in their attraction for valence electrons, that the more electronegative steals an electron from it's partner...
When an atom becomes charged we call it an.
When an atom has a positive charge it is called...
When an atom has a negative charge it's called an...
When an atom is imbalanced between protons and electrons:
More protons - postively charged
More electrons - negatively charged
The making and breaking of chemical bonds leading to changes in the composition of matter...
The starting materials in a chem reaxn are called:
The end result of chem reaxn...
The coefficient is:
The number in front of the molecule
The coefficients indicate the:
Number of molecules involved
All atoms of reactants must be:
Accounted for in the products
The point at which reactions offset eachother exactly is called:
An attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom:
H+ is a
Hydrogen Ion (Positive)
Hydroxide ion (Negatively charged)
A substance that increases the hydrogen ion concentration of a solution..
Substance that decreases hydrogen ion concentration of a solution...
In a neutral solution:
H+ = OH-
In an acidic solution:
In a basic solution:
As H+ increases:
Way less H+ than OH- (Oven cleaner, bleach)
Way more H+ than OH- (Battery acid, lemon juice)
A substance which minimizes changes in concentrations of H+ and OH- is called a:
Example of a buffer?
H2CO3 - formed when CO2 reacts with water in blood plasma
Most other buffers are also:
The number of moles of solute per liter of solution:
Molecular mass equals...
The sum of masses of all atoms in a molecule