Regents Biology Ch. 6The Chemical Basis of Life Atoms, Elements, & Molecules Why are we studying Chemistry?
Regents Biology
Ch. 6The Chemical Basis of Life
Atoms, Elements, &Molecules
Why are westudying
Chemistry?
Regents BiologyProton Neutron Electron
Hydrogen1 proton1 electron
Oxygen8 protons8 neutrons8 electrons
Everything is made of matter Matter is made of “ATOMS”
Atoms are the smallest unit
of matter
Regents Biology
Section 2.1 Atoms, Elements, and Molecules
Atomic Number – the number of protons located in the nucleus of an atom.
Atomic Mass – the number of protons and neutrons together. (also called the “Mass Number”)
Regents Biology
About 25 elements are essential for life Four elements make up 96% of living matter:
• carbon (C)
• hydrogen (H)
• oxygen (O)
• nitrogen (N)
Section 2.1 Atoms, Elements, and Molecules
Regents Biology
The World of Elements
C
Different kinds of atoms = elementsDifferent kinds of atoms = elements
H
ON
P SNa
K
Mg
Ca
Regents Biology
Molecules of Life Put C, H, O, N together in different ways to
build living organisms What are organisms made of?
carbohydrates sugars & starches
proteins fats (lipids) nucleic acids
DNA, RNA
Regents Biology
Elements come together to make compounds
Compound – A substance containing 2 or more elements.
Example Table Salt (aka – NaCl)
Elements Compounds
Section 2.1 Atoms, Ions, and Molecules
Regents Biology
Questions????