Chapter 2 - Chemistry Flashcards
What are chemicals?
The stuff that make up our bodies, the bodies of other organisms, and the environment: aka everything
What is life’s chemistry tied to?
Water - all organisms need it, and chemical reactions that occur in cells consist of 70-95% water.
All living organisms are composed of…
Matter
What is matter composed of?
Chemical elements, a substance that cannot be broken down to other substances
How many elements are there?
92
How many elements are essential to life?
25
What does CHON stand for?
Carbon, hydrogen, oxygen, and nitrogen (96% of the body)
What are trace elements?
Essential elements but only needed in very small quantities
Two or more elements combined in a fixed ratio
A Compound
Pure elements are more common than compounds
False
Smallest unit of matter that still retains the properties of an element
Atom
The three subatomic particles in atoms are:
Protons, Neutrons, and Electrons
Protons charge:
Positive
Neutrons charge:
Electrically neutral
Electrons charge:
Negative
What two subatomic particles are in the atom’s nucleus?
Neutrons and Protons
What subatomic particle orbits the nucleus?
Electrons
The atomic number has:
the number of protons in an atom
What makes up an element’s mass number?
Protons and neutrons
Atomic mass is equal to…
Atomic Number
Elements with the same number of protons as the original element but a different number of neutrons are called:
Isotopes
Do isotopes react the same as their elements?
True
Living cells can distinguish the differences between isotopes of an element
False
What determines whether atoms will form chemical bonds?
The number and arrangement of their electrons
