Name: _ANSWERS
2016 Atoms/elements, molecules/compounds and Pure vs. Mixture Quiz
IN BOLD_
Self-Testing Guide
Describing Matter
Remember when we made the atom / element foldable and learned about adrenaline and caffeine.
1. Describe the relationship between atoms and elements.
Everything is made of atoms. Elements are just a specific type of atom; there are around 100 different types.
2. Give a few examples of elements using their names and atomic symbols (The letters you see on the periodic table).
Carbon C
Gold Au
Titanium Ti
Hydrogen H
Calcium Ca
3. Describe the difference between a molecule and a compound.
If 2 or more atoms are bonded together it creates a molecule. Every chemical in the world can be called a molecule. If a molecule is
made of at least 2 different types of atoms (elements) it is also called a compound. All compounds are also molecules, but not all
molecules are compounds.
Ti
4. Describe and explain whether TiO 2
O
is a molecule, a compound or both and explain how you know.
O
Since TiO2 has at least 2 atoms in its chemical formula, it is considered a molecule, but it also has 2 different two types of atoms
(elements) in the formula so it is also considered a compound.
Pure Substances and Mixtures
Remember when we read in the textbook to find evidence for which things on the list were pure substances and which where mixtures
and did a lab where we sorted 8 things, like toothpaste and rice and beans?
5. Define and draw the concept of a pure substance; be sure to include 2 categories of pure substances.
Pure
Substance-
C
PureSubstance-
C
C
One element
C
One compound
6. Give 3 examples of ordinary pure substances.
Three examples of ordinary pure substances are copper wire, purified water and sugar .
7. Define a mixture.
A mixture is a combination of two or more substances that remain individual substances. They don’t react to become something new. It
could be difficult, but mixtures can be separated into the individual substances.
One type of matter,
like sand
+
A second type of
matter, like water
= mixture of water and sand
8. Give 3 examples of ordinary mixtures.
Three examples of ordinary mixtures are cereal in milk, rice and beans, and cola drinks.
9. When you make a mixture, do any of the ingredients change? How do you know?
The parts of a mixture do not change chemically. Banana slices in fruit salad remain banana. Sugar added to water still tas tes like sugar.
10. What defines a homogenous mixture? Give an example.
A homogenous mixture is a mixture that has ingredients spread evenly throughout. Sugar water is an example of a homogenous mixture
because it tastes the same throughout.
11. What defines a heterogeneous mixture?
Give an example.
A heterogeneous mixture is a mixture that has ingredients that ARE NOT spread evenly throughout. You would see more of one
ingredient in some parts. Chicken noodle soup is an example of heterogeneous mixture because you will have different amount of broth,
noodles and chicken in each spoonful.
12. Draw the atoms/molecules of a homogenous and heterogeneous mixture using open and filled circles
Homogenous
Spread evenly
Heterogeneous
Heterogeneous – clumps
Heterogeneous - Layers