BIO 105 - Exam 1

Science

Body of knowledge about the natural world an an evidenced based process for acquiring that knowledge.

Scientific Method

Also called process of science. The practices that produce scientific knowledge.

Observe

A description, measurement, or record of any object or phenomon

Hypothesis

An informed, logical, and plausible explanation for observations of the world

Experiment

A repeatable manupliation of one or more aspects of the natural world

Independent Variable

The variable that is manipulated by the researcher in a scientific experiment

Dependent Variable

Any variable that responds, or could potentially respond to changes in the dependent variable

Theory

A hypothesis or a cover a group of related hypotheses that has received substantial confirmation through diverse lines of investigations by independent research

Control Group

The groups of subjects in an expirement that is maintained under a standfard set of conditions with no change in the independent variable

Treatment Group

The group of subjects in an experiment that is maintained under the same standard set of conditions as the control group but is subject to manipulation of the independent variable.

Matter

Anything that has mass and occupies a volume of space.

Element

A pure substance that has distinct physical and chemical properties that can not be broken down into other substances by ordinary chemical methods

Atom

The smallest unit of an element that retains the elements distinctive properties, are the building blocks of all matter

How many protons, neutrons, and electrons does the hydrogen atom have? What are the atomic number and atomic mass of the hydrogen atom?

1 proton, 1 electron, 0 neutrons, atomic number 1, atomic mass 1.

What are the atomic number and atomic mass number on the carbon isotope shown?

The atomic number is 6, Atomic mass number is 12

Nitrogen - 11 is an isotope of nitrogen that has 7 protons and 4 neutrons. What are the atomic number and atomic mass number of nitrogen 11?Th

The atomic number is 7, atomic mass number is 11.

Isotopes

Two or more forms of an element that have the same number of protons but different numbers of neutrons

Covalent Bond

The sharing of electrons between 2 atoms

What type of bon results in one positive ion and one negative ion?

Ionic Bond

What type of bond is not a covalent bond but requires the atoms to be covalently bonded to another atom?

Hydrogen Bond, the molecules must have a covalent bond between a partially positive hydrogen atom and a partially negative atom.

What is a common feature of the valence shells of both atoms involved in covalent and ionic bonds?

Electrons, which are shared by the valence shells in covalent bonds and exchanged by the valence shells in ionic bonds

In methane gas, how many electrons is each hydrogen atom sharing? How many is the carbon atom sharing?

Hydroen is sharing one electron with carbon, while carbon is sharing four electrons with each hydrogen atom.

Carbon dioxide is not technically considered an organic compound, even though it contains a carbon atom. What essential atom is found in the organic compounds shown here that is not included in carbon dioxide?

Hydrogen is not found in CO2

In the molecule CH2O, how many electrons is the oxygen atom sharing with the carbon atom? How many is the carbon atom sharing with the oxygen atom and with each hydrogen atom?

Oxygen is sharing two electrons with carbon, while carbon is sharing two electrons with oxygen and one electron with each hydrogen atom.

Hydrogen bond

The weak electrical attraction between a hydrogen bond with a partial positive charge and a neighboring atom with a partial negative charge

Polymers

A long strand of repeating units of small molecules called monomers

Monomers

A small molecule that is a repeating unit of a polymer

Amino Acids

Any of a class of small molecules that are the building blocks of proteins

Ionic Bond

The chemical attraction between a negatively charged ion and a postively charged ion.

Polar Molecule

A molecule whose electrical charge is shared unevenly with some regions being electrically negative and other electrically positive

Where are the covalent bonds in this figure?

There are two covalent bonds located at the electrons shared between the oxygen atom and each hydrogen atom

This figure shows a water molecule. A hydrogen molecule (H2) consist of two hydrogen nuclei that share two electrons. Draw a simple diagram of a hydrogen molecule indicating the positions of the two electrons

The electrons are equidistant from the the two hydrogen nuclei because there is no difference in the strength of their attraction to the electrons

When table salt (Sodium Chloride, NaCl) dissolves in water, it separates into a sodium ion (Na+) and a chloride ion (Cl-). Which portion of a water molecule would attract the Na+ ion, and which portion would attract the Cl- ion?

The partial negative charge on the oxygen atom (O) would attract the Na+ ion, and the partial positive charge on the hydrogen atoms (H) would attract the Cl- ion.

Solution

Any combination of a solute and solvent.

Reacant

A substance that undergoes change in a chemical reaction

Products

A substance that results from a chemical reaction

Acid

A chemical compound that loses hydrogen ions (H+) in aqueous surroundings

Base

A chemical compound that accepts hydrogen ions (H+) in aqueous surroundings