Chapter 2A: Basic Chemistry Flashcards
What is matter?
A: anything that takes up space and has mass.
What is the connection between biology and chemistry?
Chemistry studies the composition, structure, and the properties of matter and the changes that matter undergoes.
Living things are composed of matter and function at the chemical level.
What is mass?
A: amount of matter in an object.
How is mass different than volume?
A: volume is the amount of space occupied.
How is mass different than weight?
A: Weight is the measure of gravitational force on an object.
Weight in change according to the…
… Amount of gravity but mass does not change.
What is an element?
A: pure substance that consists entirely of one type of Atom.
What are primary elements in living things?
Carbon, hydrogen, oxygen, nitrogen.
Elements are represented by…
Chemical symbols.
What is an atom?
The simplest particle of an element that retains the properties of that element.
What is a compound?
Two or more elements chemically combined together with say definite proportion.
What are examples of compounds?
H20: water
NaCL: sodium chloride
CO2: carbon dioxide
NH4No3: ammonium nitrate
What are subatomic particles?
Particles that make up and Atom.
What are examples of subatomic particle’s
Protons, neutrons, and electrons.
If that Atom is neutral…
The number of protons equals the number of electrons.
What is atomic number?
Identifies the number of protons and there by the identity of the element.
Examples of elements and atomic numbers…
Hydrogen: one proton
Helium: two protons
What are isotopes?
Atoms of the same element with different number of neutrons there by have different masses.
What is the biological importance of radioactive isotopes?
The nuclear decay constant rate.
Isotopes of the same number of electrons, therefore…
Behave the same.
What is mass number?
Identifies the total number of protons and neutrons.
Most elements and actually exist…
In the form of compounds.
What is the chemical formula?
Representation that identifies the kinds and numbers of atoms for each element.
The reactivity of an element depends upon the…
Electron number and arrangement since they can be gained lost or shared.
What are chemical reactions?
Changes in the composition of substances and bonds are broken and atoms are rearranged.
What is the purpose of chemical reactions?
To become chemically stable.
What are bonds?
Force of attraction hold Atoms together.
How are covalent bonds formed?
Sharing pairs
What is a molecule?
The smallest unit of a covalently bound compound.
What are examples of molecules?
H20
C6h
How are ionic bonds formed?
Formed by the transfer of electrons to form particles of therefore oppositely charged I attract
What are ions?
Atoms with a net positive or negative charge by the losing or gaining of electrons.
What is the biological significance of ions?
Nerve conduction, muscle contraction.
What is Van der Waals force?
Relatively weak forces of attraction between charged regions of different molecules.
(intermolecular forces between molecules.)
Tiny regions of positive and a negative charge for rated as a result of rapidly moving electrons.
Van der Waals are able to hold….
Different molecules together.
What are hydrogen bonds?
Form of attraction between molecules possessing hydrogen atoms with a positive charge to a negative charge portion of another molecule or within a large molecule.
What are examples of hydrogen bonds?
Water, holding strands of DNA together, folding of proteins/enzymes into particular shapes.
The covalent bonds between the hydrogen and oxygen have…
Unequal equal sharing of electrons.
Oxygen attracts…………….more strongly than hydrogen.
Electrons
In the covalent bond between hydrogen oxygen, the oxygen end of the molecule tends to have a………charge and the hydrogen and has a……… Charge.
Negative, positive.
Why is water described as being polar?
Opposite ends are oppositely charged.
The polarity of water is the basis of…………… In water.
Hydrogen bonds.
Water acts as an essential what?
Solvent
Most chemical reactions occur in…
Solution with water.
What is the solubility principal?
“Like dissolves like “
What is the meaning of the solubility principal “like dissolves like “?
Polar dissolves polar and ionic. Nonpolar dissolves nonpolar
Water possesses a high…
Specific heat
What is specific heat?
Amount of energy required to change 1 g of substance 1°C.
What is the difference between high specific heat and low specific heat?
High specific heat means the temperature changes slowly with added energy. Low specific he means the temperature changes rapidly.
Water possesses what two kinds of forces?
Cohesive forces (cohesion: sticks to itself.) Adhesive forces (adhesion: sticks to other things.)
What do cohesive and adhesive forces result in?
Surface tension: molecules on the surface are attracted to itself more than the air.
EX: penny activity
Capillary action: movement of liquids/water up due to he seven cohesive forces.
EX: TAC Wix
What are mixtures?
combination of two or more substances physically blended together; no set ratio of components.
Suspensions
A.size of particles
B.action of particles
C. Filtration of particles
D. Biologically significant examples
A. Relatively large
B. They are not dissolved, temporarily suspended by settle.
C. Particles can be filtered by paper.
D. Erosion- H20 has suspended dirt/soil.
Blood-blood cells suspended in plasma.
Colloids A.size of particles B.action of particles C. Filtration of particles D. Biologically significant examples
A. Medium in size
B. Long-term suspensions, not dissolved.
C. Cannot be filtered.
D. Milk, egg white, Jell-O, mayo.
Solutions A.size of particles B.action of particles C. Filtration of particles D. Biologically significant examples
A. Tiny/small Atoms or molecules.
B. Particles are actively dissolved.
C
D
What are the parts of a solution?
Parts of a solution include the salary or substance being dissolved and the solvent or the substance that does the dissolving.
What are examples of solutions?
Oxygen dissolved in water for fish.
What is dissociation of water?
Breaking apart the water molecule to form ions.
Pure water contains equal numbers of what?
Hydrogen ions and hydroxide ions.
What are acids?
Solutions in which the hydronium ions are greater than the hydroxide ions.
What is the taste of edible acids?
Sour.
What are acids?
Solutions in which the hydrogen concentration is greater than the hydroxide.
Increases the hydronium level
What are bases?
Solutions in which the hydroxide ions are greater than the hydrogen ions.
What is a descriptive term of bases?
Alkaline.
What are examples of edible bases?
Soup, toothpaste, bleach.
What is the taste of edible bases?
Bitter.
What is the pH scale for?
It compares relative quantities of hydrogen and hydroxide.
In the pH scale each unit of change is a… Change.
Each unit is a 10 times change
Example: and 8 to 10 change would equal 100x
The pH level solutions greatly affects……
Living things.
What is the average blood pH?
7.4. And is monitored very carefully
PH levels are key to the proper functioning of………. Which regulate virtually all biochemical processes.
Enzymes.
What are buffers?
Substances that control the pH levels for Vancharb or setting changes of pH.
Example: stomach (hydrochloric acid.)
What is energy?
The ability to do work or to cause change.
What are the six specific forms of energy?
Chemical energy, heat energy, mechanical energy, solar energy, thermal energy, nuclear energy.
Electrical energy.
Living organisms carry out what?
Thousands of chemical reactions, both simple and complex, that use or release energy.
What is the general format for chemical equations?
Reactances-yields-Products
What happens to the atoms of substances?
The bonds between atoms are broken and the atoms are rearranged.
What is activation energy?
Amount of energy required to start chemical reactions.
What is an example of activation energy?
Lighting a match with friction.
What are catalysts?
Substances that will lower the activation energy there by speeding up reaction.
What is an example of a catalyst?
Enzymes.
