Chapter 2 Study Guide Flashcards
What are found in the space surrounding the nucleus?
Electrons
How do you determine the atomic mass number?
The number of protons and neutrons
What can radioactive isotopes be used for?
Determine the ages of rocks and fossils. Detect and treat cancer. Kill bacteria that spoils food. Labels to follow the movements of substances within organisms.
What does the atomic number tell you?
The number of protons or electrons
What is the name for a substance formed by the chemical joining of two or more elements in definite amounts?
Compound
What atoms make up a molecule of water?
2 atoms of hydrogen and 1 atom of oxygen
What is the most abundant compound in most living things?
Oxygen
How do compounds compare to the elements that make them up?
They don’t compare because they’re completely different
How does a covalent bond form?
When two or more atoms share electrons
What type of ion forms when an atom loses an electron?
A negative charge; anion
What property of water causes water to form a meniscus?
Adhesion
Describe the charges found on a water molecule. What does this make water?
Hydrogen and oxygen form a covalent bond. The oxygen atoms attract a little more electrons than the hydrogen. The unequal sharing gives water a slight negative charge near the oxygen atom and a slight positive charge near the hydrogen atoms. This makes it polar.
If you stir salt into boiling water, what do you produce?
A mixture called a solution
What is the water that salt is mixed into called?
The solvent
If cells were found floating in water, what would this mixture be called?
?
Which pH values indicate the strongest acids?
Zero
What type of solution has more OH- ions than H+ ions?
Basic
What makes up lipids, starches, and DNA?
Glycerol and fatty acids. Carbohydrates. Nucleic acids.
3 particles that make up an atom
Electrons, protons, and neutrons
Why is carbon so special compared to other elements?
Carbon atoms can bond to one another and form a lot of different structures
What are the functions of proteins?
Control rate of reactions. Form bone and muscle. Transport substances. And used for growth and repair.
In a chemical reaction, what happens to the atoms?
Atoms react with each other to form new products
When hydrogen and oxygen combine to form water, what is the water?
The product
What part of a chemical reaction are the reactants?
The substances that first enter into the reaction that will be changed
What is the process that changes one set of chemicals into another set of chemicals?
A chemical reaction
What is the energy that is needed to get a reaction started called?
Activation energy
If a reaction releases energy, what is needed to make it occur?
?
If a reaction in one direction releases energy, what does the reaction is the opposite direction do?
It requires energy
What forms of energy can be released from a chemical reaction?
Heat, light, electricity, or sound
What are characteristics of enzymes?
They’re affected by temperature, pH, and regulatory molecules
What is a substance that speeds up the rate of a chemical reaction called?
A catalyst
How do enzymes affect the reactions in living cells?
Enzymes speed up chemical reactions that take place in cells
Why are atoms considered neutral?
They contain the same number of protons as electrons
How does a sodium atom form a bond with a chlorine atom?
? When sodium and chloride react, sodium loses 1 electron and chlorine gains it, making the compound sodium-chloride
What accounts for water’s properties of adhesion and cohesion?
It’s polarity. It is able to form many hydrogen bonds, which account for it’s special properties
Why is water considered a polar molecule?
Because it’s 10 protons balance out the 10 electrons. When the charges are unevenly distributed, it makes it polar.
Use solvent and solute to describe how to prepare a salt solution.
Water is the solvent because it is what dissolves the solid salt into the solution. Salt is the solute
