Chapter II : Atoms, Ions and Molecules Flashcards
What are the three forms of matter?
- solid, liquid, gas
Matter is composed of what?
- atoms, which are the smallest particle that exhibits the chemical properties of an element
What are the three ways elements are called based on the percentage by weight in the body?
- major, lesser, or trace
What are the six elements that make up a 98% of weight on the body?
- O, C, H, N, Ca, P
What are the 6 elements that make up less than 1% of the total body weight?
- S, K, Na, Cl, Mg, Fe
What the mass of protons, neutrons and electrons?
- protons = 1 amu
- Neutrons - 1 amu
- Electrons= 1/1800th
Whats the average atomic mass made up of?
- protons and neutrons
What are isotopes?
- are different atoms of the same element, have the same number of protons and electrons but different number of neutrons
What’s the most prevalent carbon isotope?
- carbon 12 (with 6 neutrons)
Why are radioisotopes unstable?
- becuase they contain excess neutrons
How do radioisotopes lose nuclear components?
- in forms of high energy radiation
What is the physical half-life?
the time for 50% of radioisotopes to become stable, can vary from seconds to thousands of years
What’s the biological half-life?
the time required for half of the radioactive material from a test to be eliminated from the body
What’s the relationship of the octect rule and chemical stability?
a complete outer shell with eight electrons increases chemical stability
What are ions?
groups of atoms with a positive or negative charge
How are ions made?
- by the loss or gain of electrons
What are cations?
positive ions, made by the loss of electrons
What are anions, and how are they made?
negative ions, made by the gain of electrons
What are polyatomic ions?
anions, composed of more than one atom
Elements in the first, second, or third columns are usually anions or cations?
cations
Which side of the periodic table is metallic?
left side
What type of bonds do cations and anions form?
ionic bonds
Sharing of bonds are called?
covalent bonds
What are isomers?
molecules with the same number and kind of elements arranged differently in space