Chapter 2 Flashcards
Define matter
Matter – anything that takes up space and has mass (weight). It is composed of elements.
What are elements composed of?
Elements – composed of chemically identical atoms:
What are three types of elements?
• Bulk elements
* Trace elements
• Ultratrace elements
What is the smallest particle of an element?
an atom
How are bulk elements required in the body?
Bulk elements are required by the body in a large amount
What are examples of bulk elements?
Nitrogen, Oxygen, Carbon, and hydrogen
How are trace elements required in the body?
required by the body in small amounts
Bulk elements make up about 95% of what?
the body (body weight)
What are the characteristics of an atom?
smallest particle of an element that has the properties of that element
What are the characteristics of an electron?
extremely small particle with almost no weight; carries a negative electrical charge and is in constant motion around an atomic nucleus
What are the characteristics of a proton?
relatively large atomic particle; carries a positive electrical charge and is found within an atomic nucleus
What are the characteristics of a neutron?
particle with about the same weight as a proton; uncharged and thus electrically neutral; found within an atomic nucleus
What are the characteristics of an ion?
Particle that is electrically charged because it has gained or lost one or more electrons
What is a molecule?
particle formed by the chemical union of two or more atoms
What are atoms composed of?
subatomic particles such as; protons, neutrons, and electrons
What are characteristics or an atomic nucleus
• Central part of atom
• Electrons move around
*composed of protons and neutrons the nucleus
What defines an element?
the number of protons
What are examples of trace elements?
Cobalt, copper, fluorine, iodine, iron, maganeseum, zinc
What is the atomic number?
number of protons in the atoms of a particular element
What is the atomic weight of an atom?
The number of protons plus the number of neutrons
How do you know the number of neutrons an atom has?
Atomic number (protons) minus the atomic weight (protons and neutrons)
What are isotopes?
• Atoms with the same atomic number but different atomic weights
What isotopes are radioactive?
unstable isotopes meaning they may have unstable atomic nuclei that decompose, releasing energy or pieces of themselves until they reach a stable form.
Ex of elements with radioactive isotopes: O2, iodine, iron, phosphorus, and cobalt
What element often forms isotopes?
Oxygen (O16, O17, O18)