2.2 ELEMENTS/ ATOMS LECTURE

this is the easy stuff?????? tweaking.

what makes up matter?

elements

can elements be broken down into simpler substances by ordinary chemically methods?

no

what are the 4 elements that make up the human body?

CHON. Carbon, hydrogen, oxygen, and nitrogen

define atom

derived from greek word atomos, means indivisble, they make elements and each atom has unique properties . (can infer properties by periodic table)

how many and what parts make up an atom?

3 parts . protons , neutrons, and electrons

define amu

stands for atomic mass unit. weight used to describe 1 proton or neutron. (electrons are too small to be weighed)

define protons

has positive charge. is equal to one amu. located in nucleus.

define neutrons

has neutral charge. is slightly heavier than 1 amu. located in nucleus.

define electrons

located in outer electron shells. has negative charge . so small their weight is not considered.

define atomic symbol

letter on periodic table that stands for element name

what is located in the nucleus?

protons and neutrons

Isotopes

an atom of the same element that has same # of protons with varying neutrons.

Radioisotope

isotopes that decay to stable form. Neutrons will decay to protons causing atom to change to different element. # of electrons DOES NOT equal number of protons for radioisotopes. This release of energy = radiation hence “radio” isotope.

If radioisotope loses half of itself this is called?

half life

atomic number

number of protons in nucleus. written as subscript left of atomic symbol

mass number

number of protons and neutrons in nucleus. total mass written as super script. (this is NOT the same as atomic wieght)

Atomic weight

average weight of all mass numbers , isotopes, etc recorded.