Download K,7th Grade Test Review: Atoms and Chemical Reactions PART

K,7th Grade Test Review: Atoms and Chemical Reactions
PART ONE: Fill in the word next to its definition or description. USE YOUR NOTES HANDOUTS!!!
Protons
Negative
Element
Atomic Mass
Stable
Democritus
Neutrons
Charge
product
Atomic Number
Chemical Formula
Bohr
Electrons (use twice)
Nucleus
Reactant
Chemical Reaction
Chemical Change
Lavoisier
Positive
Atom
Isotope
Chemical Equation
Mass
Dalton
1. __________ is the smallest unit of an element that is still that element.
2. __________ is a substance that cannot be broken down into similar substances by physical or
chemical changes.
3. Protons and neutrons have a __________ of 1 unit. Electrons have almost none.
4. An atom with more protons than electrons, it has a _____________ charge. And is called a
cation.
5. The _________________ number of an element is the number of protons in each atom. The
periodic table is arranged from smallest to largest _____________________. (same term)
6. _____________ are found in the nucleus of atoms and determine which atom it is. They have a
positive charge.
7. ____________ are found in the nucleus of atoms. They have no charge.
8. ______________ whiz around the nucleus in a cloud and have a negative charge.
9. _________________________ is equal to the number of protons plus the number of neutrons in
an atom.
10. When two atoms are the same element but have different numbers of neutrons, they are called
_______________________.
11. ___________ is how positive or negative an atom is. You calculate by subtracting the number of
electrons from the number of protons.
12. A _______________ shows how many atoms of what elements are in a molecule.
13. An atom with more electrons than protons has a _____________ charge and is called an anion.
14. Protons and Neutrons are found in the ______________ of the atom.
15. A ___________________ shows substances you start and end with in a reaction connected by
an arrow.
16. A ________________________ is when you rearrange the atoms in a set of substances to create
new substances. It can also be called a __________________________.
17. Molecules react with each other because the atoms want to be more ___________________.
18. When atoms bond with each other, it is because of their __________________ (a part of the
atom).
19. The substances you start with in a reaction are called the ____________________.
20. The substances you end up with in a reaction are called the _____________________.
21. _______________ was an ancient Greek who first wrote about the idea of atoms.
22. ________________ was a scientist who came up with atomic theory.
23. _________________ was one of the first scientists to make a model of the atom.
PART TWO: Parts of the Atom
24. Label the parts of this box from the periodic table.
10
Ne
Neon
20.2
25. Fill in the blanks using the information above.
a. How many protons does Neon have?
______________ protons
b. How many neutrons does neon have?
_____________ neutrons
c. How many electrons does neon have if it has a charge of zero?
____________ electrons
d. DRAW A PICTURE OF NEON. Be sure to put the right number of protons and neutrons in the
nucleus, label the nucleus and draw the electrons outside.
PART THREE: Calculating Charge and Counting Electrons
1. An oxygen atom has 8 protons and 10 electrons. What is its charge?
2. A Lithium atom has 3 protons and 2 electrons. What is its charge?
3. A Nitrogen atom has a charge of 3- and atomic number 7. How many electrons does it have?
4. An unknown atom has 2 electrons and a charge of zero. What is its name and atomic
number?
5. When an atom is positive, what is it called?
6. When an atom is negative, what is it called?
PART FOUR: Chemical Equations.
For each equation, label the products and reactants. Then, count the number of atoms of
each element on each side. Then fill in the blanks.
1. Ca(OH)2
#Ca:
#O:
#H:
#C:
+
CO2

CaCO3 + _________
#Ca:
#O:
#H:
#C:
2. NaHCO3
#Na:
#H:
#C:
#O:
#Cl:
+
HCl

NaCl + ______________ + _______________
#Na:
#H:
#C:
#O:
#Cl:
3. ____Fe +
#Fe:
#O:
_____ O2

FeO3
#Fe:
#O:
QUESTIONS
4. What does the arrow in the equation stand for?
5. Why do the numbers of each element on both sides have to match up?
6. What scientists studied the way chemical reactions happen and proved that nothing was
created or destroyed, only changed?