A mixture is a substance that includes more than one type of element and/or compound that are not bonded together.
100
Define the word “compound.”
A compound is a substance whose smallest particles include more than one element chemically bonded together.
100
What exactly is a chemical formula? (What is the definition?)
A chemical formula gives the symbols and amounts of each type of atom in a compound.
100
Define an ion.
An atom that has a positive or negative electric charge. Ions are created when atoms gain or lose electrons.
100
Draw the Lewis Dot Diagram for gallium (Ga).
*
Ga *
*
200
How can a mixture be separated into its original parts?
A mixture can be separated by physical means, using the properties of the substances in it.
200
How many compounds can be made from the atoms on the Periodic Table?
Millions!
200
Write the chemical formula for carbon dioxide ( 1 carbon atom and 2 oxygen atoms)
CO2
200
How does an ionic compound differ from a covalent compound?
Instead of sharing electrons, one element in an ionic compound gives away an electron to the other element in the compound. Each atom will then have an electric charge.
200
Draw the Lewis Dot Diagram for silicon (Si).
*
* Si *
*
300
What is a homogenous mixture?
A homogenous mixture is exactly the same all the way through, every spoonful or portion is the same.
300
What is a chemical bond?
A chemical bond is when a bond is formed between atoms by the sharing or transferring of electrons.
300
Write the chemical formula for glucose.
A molecule for glucose has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
C6H12O6
300
What keeps an ionic compound together?
The atoms in ionic compounds are attracted to each other by their electric charges.
Each positive ion is attracted to all of the neighboring negative ions, and vice-versa.
300
Draw the Lewis dot diagram for magnesium.
*
Mg *
400
What is a heterogenous mixture?
A heterogenous mixture is unevenly mixed, and not the same all the way through.
400
Define a covalent bond.
A type of chemical bond that is formed by sharing electrons.
400
Does the chemical formula for a compound determine its properties?
No, the properties of a compound depend upon the structure of the molecule (its shape and form).
400
Which two groups are the most reactive, and why?
Group 1 (alkali metals ) and Group 7 (halogens) because they are very close to the magic number (only have to share or give away 1 electron to get to same number of valence electrons as a noble gas - 8)
400
Draw the Lewis dot diagram for methane (CH4)
H
**
H : C : H
**
H
500
Why is water called “The Universal Solvent?”
Water is called “The Universal Solvent” because almost everything that dissolves will
dissolve in water.
500
Define “molecule” and give two examples
A molecule is a group of atoms held together by covalent bonds.
Some examples are:
methane (CH4), ammonia (NH3), oxygen (O2), nitrogen (N2) and water (H2O).
500
Is it possible for two or even three compounds to have the same chemical formula, but different structures and properties?
Yes. An example is C9H8O4, which is the formula for aspirin. The same atoms could be put together in different structures to form two very different compounds.
500
Explain why the Noble Gases are not reactive.
Noble gases have 8 valence electrons and this means that they don’t have to share or get any electrons to get to the magic number - they are already there.