2 The Chemical Context Of Life Flashcards
What is an element?
A substance that cannot be broken down to other substances by chemical reactions.
What is matter?
Anything that takes up space and has mass
What is a compound?
A substance consisting of two or more different elements combined at a fixed ratio.
How many elements are essential to life?
25/92 elements are essential to life.
What elements make up living matter and what percent does it make up?
Oxygen (O), Carbon (C), Hydrogen (H), and Nitrogen (N) make up 96% of living matter.
What is a Trace Element?
A Trace Element are elements needed by an organism but only in minute quantities.
Give two examples of Trace Elements.
Iron (Fe) and Iodine
What is an Atom?
An atom is the smallest unit of matter that has properties of an element.
What is smaller than an atom? Give an example.
Subatomic particles are smaller than an atom.
- Protons +
- Neutrons
- Electrons -
What forms the atomic nucleus?
Protons and Neutrons form the atomic nucleus.
What is an Atomic Number?
The Atomic Number is the number of protons unique to that element.
What is the Mass Number?
The mass number is the total of protons and neutrons in an atom.
What is a Radioactive Isotope?
An Isotope which the nucleus decays spontaneously, giving off particles and energy.
What happens to Radioactive Isotope after they decay?
The decay leads to change in the number of protons and becomes an atom of a different element.
What is energy?
The capacity to cause change.
