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Basic Chemistry Review Questions
Mr. Haas
1) Composed of only one type of atom, over 100 types of these have been
discovered. ELEMENTS
2) An atom is given a certain elemental name based on the # OF PROTONS
3) What is an isotope? Give an example of an isotope.
ISOTOPES ARE DIFFERENT VARIATIONS OF THE SAME ELEMENT
BECAUSE OF DIFFERENT NUMBERS OF NEUTRONS. Carbon 14
4) How many protons, neutrons, and electrons does Chlorine have? 17 PROTONS,
18 NEUTRONS, 17 ELECTRONS
a. What is the atomic mass? Atomic number? 35.4, 17
b. If you were to somehow remove a proton from the atom, what would it
become? SULFER
c. An isotope of this element is known to have an atomic mass of 37. How
many neutrons does this isotope have? 20
5) An atom containing fewer electrons than protons has a POSITIVE charge.
6) What is an ion? AN ATOM WITH AN UNEQUAL NUMBER OF PROTONS
TO ELECTRONS, GIVING THE ATOM AN OVERALL CHARGE.
7) Na+Cl- or K+Cl- is an example of an ionic bond.
8) Ionic bonds form when one element DONATES it’s electrons to another element.
9) Water consists of an atom of OXYGEN that has formed a COVALENT bond
with two atoms of hydrogen.
10) Explain the difference between an ionic bond and a covalent bond. AN IONIC
BOND IS WHEN ATOMS GIVE/TAKE ELECTRONS CREATING CHARGED
ATOMS (IONS) WHICH CAUSES THEM TO INTERACT WITH ONE
ANOTHER. (OPPOSITES ATTRACT) A COVALENT BOND IS THE
SHARING OF ELECTRONS BETWEEN ATOMS WITHOUT A CHARGE.
THE MAIN DIFFERENCE IS THE GIVE/TAKE VS. SHARING OF
ELECTRONS.
11) The number of protons in an atoms nucleus is the ATOMIC NUMBER.
12) An ion can have either a POSITIVE or a NEGATIVE charge.
13) How many electrons can the energy level nearest the nucleus hold? 2 What is this
level (shell) called? K SHELL
14)
a. Name the element of each of the atoms below.
b. How do you know? (Include the atomic mass for each in your answer)
A. HYDROGEN
HELIUM
HELIUM
AM=3, ONLY 1 PROTON
AM=3, 2 PROTONS
AM=4, 2 PROTONS
15) Describe the bonding of a potassium ion (K+) with a chlorine ion (Cl-). IONS
ATTRACT THEIR OPPOSITE CHARGE AND THEIR INTERACTION IS
CALLED AN IONIC BOND.
16) Draw the Lewis dot structure of NH3 picture should show a pair of dots around N
and 3 single dots around N each used to form a covalent bond with 3 different H.
17) Explain why atoms made up of charged particles have overall charges of zero.
PROTONS ARE + AND ELECTRONS ARE – SO ATOMS WITH EQUAL
NUMBERS OF THESE 2 HAVE AN OVERALL CHARGE OF 0. (ADD THEM
TOGETHER)
18) The elements listed below bond together either by ionic or covalent bonds. Write
the type of bond that forms between the elements.
Example: Na+
ionic
ClH2
COVALENT
O
B
COVALENT
H3
COVALENT
O2
IONIC
I2-
C
2+
Pb
19) Explain how pH paper works and why water has a pH of 7. H+ or OH- ions hit
the paper and react with it. Water is neutral because in solution (not ice or gas) it
effectively acts like H+ and OH- ions. Since you have an equal number of both
ions contacting the paper, it registers as pH 7 or neutral.
20) You accidentally spill ammonia (a strong base) into your soup but still really want
to eat it. How could you fix the soup so it would not be harmful? Add a strong
acid to buffer the strong base, making it as close to neutral as possible.
21) Explain how and why carbon dating works. It works because carbon-14 is unstable
(radioactive), an isotope and wants to become stable by converting itself into carbon-12.
Because we know exactly how long this takes, we can analyze a sample to see the ratio
that remains of carbon 14 to carbon 12.
22) Why is pH so important for metabolism? Metabolism is the sum of all the reactions in
your body. These reactions work best at certain values of pH.
23) Explain how TUMS work. TUMS are basic and help to neutralize (buffer) stomach acid
which is what is causing the heartburn.