Atoms and Ions Elements, Compounds, Mixtures Organic Compounds Enzymes & Reactions Molecules
True or false? The three particles making up all atoms are protons with positive charge, neutrons with no charge, and electrons with negative charge.
True.
The nucleus of a helium atom contains: (a.) protons only. (b.) protons and neutrons. (c.) protons and electrons. (d.) electrons only.
(b.) protons and neutrons
How does one calculate the mass of an atom?
Add together the number of neutrons and protons in the nucleus.
A sodium ion has 21 protons and 20 electrons. What kind of electrical charge does it have?
positive charge
The atomic number of oxygen is eight. What does this tell us about an oxygen atom?
Every oxygen atom has 8 protons in its nucleus.
True or false? A methane molecule contains one carbon atom and two hydrogen atoms.
False. A methane molecule contains one carbon atom and four hydrogen atoms
A covalent bond is a link between two...?… sharing a pair of …?… (a.) atoms……protons. (b.) ions ……. electrons. (c.) ions ……. neutrons. (d.) atoms ….. electrons.
(d.) atoms ………electrons.
What is a molecule?
A particle containing two or more atoms connected by covalent bonds.
Draw a diagram showing the number, kinds, and arrangement of atoms in a carbon dioxide molecule.
OOC
Explain what it means to say that a water molecule is polar.
A water molecule has a partially positive region around the hydrogen atoms and a partially negavite region around the oxygen atom.
True or false? All the atoms making up an element are alike.
True.
Properly match the examples in the first row with the categories in the second row. EXAMPLES air aluminum water CATEGORIES element compound mixture
Air is a mixture. Aluminum is an element. Water is a compound.
What do we call a substance containing two or more elements chemically combined?
compound
What is the pH range for (a.) an acid, (b.) a base, and (c.) a neutral solution?
Acids range from 0-7, bases range from 7-14, and neutral solutions are close to 7.
Define and give an example of a solution.
A solution is a mixture in which the molecules of one substance are equally distributed among the molecules of another substance. Examples include salt water or sugar water.
True or false? All compounds containing carbon are organic compounds.
False. Compounds like carbon dioxide, marble, and baking soda with carbon covalently bonded to oxygen are inorganic and do not turn black when heated.
Which of the following types of organic molecules are made by linking together amino acids? (a.) carbohydrates (b.) lipids (c.) proteins (d.) nucleic acids
(c.) proteins
What three elements make up carbohydrates, and in what proportions?
1 part carbon 2 parts hydrogen 1 part oxygen
What are the building block molecules of DNA and RNA?
nucleotides
What is one difference between saturated and unsaturated fats?
Saturated fats have no C=C bonds and are solid at room temperature. Unsaturated fats have C=C bonds are are liquid at room temperature.
True or false? Most enzymes are proteins.
True.
Chemical reactions convert: (a.) reactants into products. (b.) catalysts into enzymes. (c.) substrates into active sites. (d.) products into reactants.
(a.) reactants into products.
The energy needed to start a chemical reaction is called what?
activation energy
What is the function of enzymes in organisms?
Enzymes speed up chemical reactions necessary for life.
Energy cannot be created or destroyed. Where does the energy come from to produce the heat when methane burns?
When the carbon-hydrogen bonds of methane break, chemical energy in the C-H bonds is converted into heat energy.
Team scores Period:4Date: Jan. 02, 2007 PROKARYOTES 0000 EUKARYOTES 0000