Chapter 2 Flashcards
Define the term- anything that occupies space and has mass
Matter
What are the three states of matter?
Solid, Liquid, and Gas
Define the term- substances that cannot be broken into other substances
Elements
How many elements occur naturally on Earth?
92
How many of those elements are essential to life?
25
Which 4 elements make up 96% of the weight of a human body?
Bonus- name the percent of each
Hydrogen- 9.5%
Nitrogen- 3.3%
Carbon- 18.5%
Oxygen- 65%
What does an iodine deficiency cause?
Goiter
What element has been added to water to decline tooth decay?
Fluoride
What is a compound?
What is salt comprised of?
Is made up up of two elements in a fixed ration
Example- NaCl, Sodium Chloride
What is the smallest unit of matter that still retains properties of an element?
Atom
Define the term- the central core where protons and neutrons are packed tightly.
Nucleus of an atom
What is the atomic number of an element?
number of protons
used to determine which element is present
What is the atomic mass of an element?
The number of protons and neutrons together
Define the term- the mass of a proton and the mass of a neutron are almost identical and are expressed in a unit of measurement.
Dalton
What is equivalent to 1 dalton?
The masses of protons and neutrons
____ are alternate mass forms of an element.
Isotopes
T/F- Isotopes have the same number of electrons and neutrons and DIFFERENT number of protons.
False, Isotopes have different numbers of neutrons NOT protons
What is it called when the nucleus of an element decays which gives off particles and energy?
Radioactive Isotopes
Which of the following is a radioactive isotope?
Carbon-12
Carbon-13
Carbon-14
Carbon-14
What are the 2 uses of radioactive isotopes?
Nuclear Power Plants and PET Scans
By definition, all atoms of carbon have exactly 6 ___, but the number of ____ vary from one isotope to another.
Protons, Neutrons
Define the term- an attraction between 2 atoms resulting from a sharing of outer shell electrons or the presence of opposite chargers on the atoms
Chemical Bonding
Define the term- an atom or molecule that has gained or lost one or more electrons thus acquiring an electrical charge
Ions
How many electrons are gained or lost for the compound NaCl?
Sodium has a +1 charge while chlorine will have a -1 charge