Module 2: Intro To Chemistry Flashcards
Chemistry is the science of the structure and interactions of matter, which is anything that occupies space and has mass
Describe the structure of an atom
Units of matter of all chemical element consist of a nucleus (positively charged protons and neutral neutrons) and negatively charged electrons that move about the nucleus in different energy levels.
Define the term isotope
Different atoms of the same chemical element that have the same number of protons but different numbers of neutrons. A radioactive isotope is unstable and emits radiation (energy).
Define ion
If an atom either gives up or gains electrons it becomes an ion. Which is an atom that has a positive or negative charge due to its unequal number of protons and electrons.
Define molecule
When 2 or more atoms share electrons, the resulting combination is called a molecule
Define compound
The combination of 2 or more different atoms. Ie: water=H2O
Define a free radical
An electrically charged atom or group of atoms with an unpaired electron in its outermost shell. Free radicals become stable by either giving up their unpaired electron or by taking on an electron from another molecule
Define an antioxidant
Substances that inactivate oxygen - derived free radicals
The atoms of a molecule are held together by forces of attraction called chemical bonds. Describe the different types of chemical bonds.
Ionic bonds, covalent bonds and hydrogen bonds
Describe an ionic bond
When an atom loses or gains a valence electron, ions are formed. Positively and negatively charged ions are attracted to one another. When this force of attraction holds ions of opposite charges together, an ionic bond results.
What are cations?
Positively charged ions. Anions are negatively charged ions.
Ionic bonds are _______ than covalent bonds but ______ than hydrogen bonds.
Weaker, stronger
Ionic compounds exist as solids but in solution some may dissasociate into positive and negative ions. Such a compound is called an ____.
Electrolyte
What are covalent bonds and how are they formed?
When the atoms of molecules share electrons. Covalent bonds are the most common chemical bonds in the body. Covalent bonds can be nonpolar or polar.
Covalent bonds are the ____ bonds.
Strongest
The polar covalent bonding of hydrogen to oxygen or nitrogen allows for ____ bonds to form.
Hydrogen
What are hydrogen bonds?
2 other atoms (usually oxygen or nitrogen) associate with a hydrogen atom
_____ bonds are weak and cannot bind atoms into molecules; instead, these bonds serve as links between molecules to provide strength to help determine the 3 dimensional shape of large molecules.
Hydrogen bonds
How does a chemical reaction occur?
When new binds are formed or old bonds break between atoms
The starting substance of a chemical reaction are known as the ____. The ending substances of a chemical reaction are the _____.
Reactants, products
What is the law of conservation of mass?
The total mass of the reactants equals the total mass of the products
____ refers to all the chemical reactions occurring in an organism.
Metabolism
Energy is the capacity to do work. Describe the different forms of energy.
Potential energy, chemical energy and kinetic energy
What is potential energy?
The energy stored by matter due to its position (ball at top of hill)
What is chemical energy?
A form of potential energy stored in the bonds of compounds or molecules.
What is kinetic energy?
The energy associated with matter in motion.
Describe the types of chemical reactions
Synthesis reaction, decomposition reaction, oxidation and reduction
What is a synthesis reaction?
Occurs when 2 or more atoms, ions or molecules combine to form new and larger molecules. The reactions are anabolic which means that bonds are formed.
Describe a decomposition reaction.
A molecule is broken down into smaller parts. These reactions are catabolic which means that chemical bonds are broken in the process.
In oxidation-reduction, electrons are taken from the atom being oxidized by the atom being reduced. What is oxidation?
The loss of electrons from a molecule, which results in a decrease in the potential energy of the molecule.
What is reduction?
The gain of electrons by a molecule which results in an increase in the potential energy of the molecule.
Differentiate between organic and inorganic compounds.
Inorganic compounds usually lack carbon and are simple molecules; whereas organic compounds always contain carbon and hydrogen, always have covalent bonds and usually contain oxygen.
Discuss the properties of water
The most important and abundant inorganic compound. Water enables reactants to collide to form products. Water dissolves wastes. A major part of mucus and lubricating fluids. Water has a high heat capacity.
The most important property of water is its polarity. Describe what that means.
In the water molecule the uneven sharing of valence electrons confers a partial negative charge near the single oxygen atom and two partial positive charges near the two hydrogen atoms.
Describe hydrolysis
Breaks large molecules down into simpler ones by adding a molecule of water.
What is dehydration synthesis?
Occurs when 2 simple molecules join together, eliminating a molecule of water in the process.