Chapter 2-Chemistry Flashcards
Capacity to do work or put matter into motion
Energy
Energy in action
Kinetic energy
stored energy, that is, inactive energy that has the potential, or capability, to do work but is not presently doing so.
Potential energy
the form stored in the bonds of chemical substances.
Chemical energy
In your body, electrical currents are generated when charged particles called _________ move along or across cell membranes.
Ions
energy directly involved in moving matter.
Mechanical energy
energy that travels in waves.
Radiant energy
What form of energy is found in the food we eat?
Chemical energy
What form of energy is used to transmit messages from one part of the body to another?
Electrical energy
What type of energy is available when we are still? When we are exercising?
Potential energy (PE) is available when we are still. When we exercise, PE is converted to kinetic (working) energy, specifically to mechanical energy.
A combination of two or more atoms held together by chemical bonds is called
Molecule
If two or more atoms of the same element combine, the resulting substance is called
A molecule of that element
When two hydrogen atoms bond, the product is a molecule of hydrogen gas and is written as H2
When two or more different kinds of atoms bind, they form molecules of a
A compound
homogeneous mixtures of components that may be gases, liquids, or solids.
Solutions
the mixture has exactly the same composition or makeup throughout
Homogeneous
The substance present in the greatest amount is called
The solvent
any element or compound is equal to its atomic weight or molecular weight (sum of the atomic weights) in grams.
Mole
Heterogeneous mixtures often appear translucent or milky and although the solute particles are larger than those in true solutions, they still do not settle out
Colloids (aka emulsions)
heterogeneous mixtures with large, often visible solutes that tend to settle out.
Suspensions
Anything that has weight and takes up space
Matter
A substance that cannot be broken down into a simpler form by ordinary chemical reactions
Element
Four most abundant elements in the human body
Oxygen, hydrogen, nitrogen, and carbon
Basic unit of matter
Atom
Three subatomic particles of an atom
Protons, neutrons, and electrons
Where is the proton located in the atom?
What type of charge does it have?
In the nucleus
Positive charge
Where are the neutrons located in the atom?
What type of charge does it have?
In the nucleus
Doesn’t have a charge (neutral)
Where are the electrons located in the atom?
What type of charge does it have?
Orbit around the nucleus
Carry a negative charge
Ion with a positive charge
Cation
Ion with a negative charge
Anion
Type of bond where electrons are shared between atoms
Covalent bond
Formed by hydrogen bond, holds water molecules together
Surface tension
Weakest of all bonds
Hydrogen bonds
When alcohol is a solvent
Tincture
When water is the solvent
Aqueous solution
A molecule that releases hydrogen ions when added to water
Acids
A molecule that accepts hydrogen ions when added to water; bitter taste
Bases
Resists the changes in pH
Buffer
