Chapter 2 Flashcards
List the subatomic particles and describe the charge and location of each
Protons-positive-in nucleus
Neutrons-neutral-in nucleus
Electrons-negative-circle the nucleus
Define matter and atom
Atoms are the basic unit of matter matter is anything that takes up space
What is an element
A pure substance consisting of one type of atom
What is the atomic number represent
Number of protons in the nucleus
What does the atomic mass represent
Average of all the isotopes
How do you calculate the number of neutrons and then atom
You round the atomic mass and subtract the atomic number from it
What is an isotope
Atoms of the same element with different numbers of neutrons
What is it mean women isotope is radioactive
Their nucleus is unstable and breaks down at a constant rate overtime
If some beneficial uses of radioactive isotopes
It can treat cancer, date rocks, and kill food spoiling bacteria
What is the difference between the oxidation number and the valence number
Oxidation numbers how many valence electrons and lemon needs to gain or lose to become stable, valence numbers are the number of electrons in the last ring
What is the period Number tell you
The number of electrons rings
What’s a compound
The chemical combination of two elements in definite proportion
What is the purpose of Atoms forming chemical bonds
To become stable
Distinguish between covalent and ionic bonds
Covalent-atoms share electrons
Ionic-electrons are transferred
Give an example of a compound containing an ionic bond
NaCl
What is the difference between polar and nonpolar covalent bonds
Polar- unequal charge
Nonpolar- equal charge
What type of bond does water contain
Polar covalent bonds
Describe the structure of water
Two hydrogen atoms and one oxygen atom (polar covalent bond)
How do Vanderwall’s forces occur
When molecules are close together, a slight attraction can develop between the oppositely charged regions of nearby molecules
Given example of a Vanderwall’s force
A gecko’s foot
How are hydrogen bonds formed
Attraction between a hydrogen atom with a partial positive charge and and an atom with a partial negative charge
Describe Capillary action and explain how hydrogen bonds aid in this process
Adhesion between water in the tree causes water to rise within The tree. Hydrogen bonds help to create adhesion
Explain how hydrogen bonds allow ice to Float
They push the atoms away from each other causing water to have a lesser density
Why is the property of water that ice is less dense important in biology
So ice floats at the surface of the water through and insulates fish under the sea and to make sure the ocean does not freeze
Explain how hydrogen bonds allow water to have a high specific heat
Hydrogen bonds cause atoms to move less which causes the atoms to respond less to heat
What is the biological importance of waters high specific heat
So our blood doesn’t boil
What is a mixture
When two or more elements mixed together but are not chemically combined
Describe the two types of mixtures and give examples of each
Solutions- all components are evenly distributed- sugar water
Suspensions- movement of molecules keeps small particles suspended-blood
Explain how water dissolves particles
It can dissolve ionic compounds/other polar molecules
What types of molecules can water dissolves
Polar molecules
What types of molecules can water not dissolve
Nonpolar molecules
Describe dissociation
A hydrogen nuclei leaves it’s electron behind with the oxygen atomto become a hydrogen ion, while the oxygen and other atoms become a hydroxide ion
What makes a solution and acid
It forms h+ ions in a solution
What makes a solution a base
It produces hydroxide in a solution
Describe the pH scale? What do the numbers represent?
The pH scale is a measurement system that indicates h+ ions in a solution acids are 0 to 6 neutral are seven bases are 8 to 14
Why is water neutral
Equal number of h+ and hydroxide ions
How do you buffers maintain pH
Buffers are weak acids and bases that react with strong acids and bases to neutralize them
