1
A mixture that cannot be separated and is uniform throughout is also known as a ______ mixture.
Homogeneous
Substances that release hydrogen ions when dissolved in water are called____.
Acids
A mixture that can react with an acid or base to keep pH within a certain range is called a ______.
Buffer
The building block of matter.
Atom
Italian dressing settles out, or becomes separated because it is a ____ mixture.
Heterogeneous
How many electrons can the 2nd valence shell hold?
8 electrons
On the periodic table the rows are called _______.
Periods
Substances that release hydroxide ions when dissolved in water are called____.
Bases or Alkaline
Each square on the periodic table represent a/an _____.
Element
What charge does a proton have?
Positive
Two or more atoms of the same element having different numbers of neutrons is known as a/an _____________.
Isotope
The water in salt water would be what part of the solution?
Water is the Solvent
Define the nucleus of an atom.
The nucleus is found in the center of an atom and contains protons and neutrons.
How many covalent bonds does 1 H2O molecule have?
2 Covalent Bonds
If an element has an atomic number of 7 and an atomic mass of 14, how many electrons will this element have?
7 electrons
Explain what a coefficient is in a chemical equation.
The big number in front of a molecule.
ex) The 2 in 2NaCl
A weak interaction between a hydrogen atom and a fluorine, oxygen, or nitrogen atom is called a/an ___.
Hydrogen Bond
How do you find how many neutrons are in an element when you are looking at an element on the periodic table?
You subtract the atomic number from the atomic mass.
Atomic Mass - Atomic # = a positive number
If you have an element with an atomic number of 9 and an atomic mass of 18, how many electrons will be found in the 2nd valence shell?
7 electrons
2- will fill the first shell
7- will fill the second shell
What type of bond is holding NaCl together?
Ionic Bond
True or False. Van der Waals forces are attractive forces between molecules.
True
What type of bonds are holding a H2O molecule together?
Covalent Bond
Explain what an Ionic Bond is
Where an electron is gained or taken away between two or more elements.
What is the atomic structure difference between Carbon-12 and Carbon-13?
Carbon-13 has one more neutron in its nucleus.
On the periodic table it looks like there is a stair step because of how elements are classified, everything to the left of the stair step are ___________.
Metals