semester exam review Flashcards
in which area of biology is DNA most likely to be studied
information and heredity
What is science
an organize way of gathering and analyzing evidence about the natural world
everything we know about the natural world
what is the first step of the scientific method
State the problem
what is a theory
when evidence from numerous experiments supports the hypothesis
what is data
The info you collect during your observations
what is a hypothesis
a proposed scientific explanation for a set of observations
what are the goals of science
to provide natural explanations for natural events in the world, understand patterns to make predictions about future events
how many variables should you test at one time
1
what is the basic unit of length in the metric system
meter
what questions cannot be answered in science
questions outside the natural world
why do all scientists the metric system
it is convenient to all use the same system and easier to convert without conversion factors
what types of molecules will not dissolve in water
Nonpolar molecules
what is the mass number
the average weight of all isotopes of that element
protons and neutrons
if an atom loses electrons what charge would have
positive
what are Van der waal’s forces
when molecules move together the slight positive and negative regions can create attraction
how is a suspension different from a solution
a solution has a solute being dissolved in a solvent
suspension is a mixture of water & non dissolving particles
The electrons located in an atom
in the electron cloud
what is the atomic number
number of protons or electrons in the atom
on the pH scale what is the most acidic number
0
how does the ion concentration of a base differ from an acid
acids have more hydrogen ions
bases have more hydroxide ions
explain why water is polar
water molecules attract to each other in hydrogen bonds
what is a compound
substance formed by the chemical combination of 2 or more elements in a definite proportion
what is an isotope
atoms of the same element that have the same number of protons but different numbers of neutrons
what type of electrons participate in bonds
valence