1.1 Chemical Elements Flashcards
What is matter?
Anything that has mass and takes up space
What are the states of matter?
Solid, liquid, gas, plasma (generally excluded)
All matter is composed of how many naturally occurring elements?
92 elements
What is an element?
A substance that cannot be
broken down to simpler substances by ordinary chemical means. Made of atoms. Each have unique properties.
What are the 6 elements that make of 95% of the body weight of organisms?
CHNOPS - carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur.
What is an atom?
The smallest unit of an element that still has the element’s properties. Made of specific numbers of subatomic particles: protons, neutrons, and electrons.
What is a proton?
Positively-charged subatomic particle found in the atomic nucleus.
What is a neutron?
Neutrally-charged subatomic particle found in the atomic nucleus.
What is an electron?
Negatively-charged subatomic particle orbiting around the nucleus in the electron shell
What is atomic number?
The number of protons and electrons of an element (assuming neutral charge). Accounts for unique properties of the atom.
What is mass number?
Sum of number of protons and neutrons in a nucleus.
How do you write an atom by itself?
Put the mass number as a left superscript of the atomic symbol and the atomic number a left subscript.
What is atomic mass?
The average mass for all isotopes of that atom.
What is an isotope?
Atoms of the same element differing in number of neutrons. They have different atomic masses.
How do you find the number of neutrons?
Atomic mass - atomic number (number of protons) and round to the nearest whole number.
What are groups on the periodic table?
Vertical columns.
What are periods on the periodic table?
Horizontal rows.
How does atomic mass change as you move down a group or across a period?
It increases.
Who developed the periodic table?
Dimitri Mendeleev.
What is amu? What is the amu of the subatomic particles?
Atomic Mass Unit. Protons and neutrons are each 1 amu; electrons are 0 amu.
What is a Geiger counter?
An instrument used to measure radiation.
How does the chemical behavior of a radioactive isotope differ from a stable isotope of the same element?
The chemical behavior is the same.
What are tracers, and how are they used?
They are radioactive isotopes used in a small amount; when in the body, its location and activity can be tracked. Radioactively labeled glucose can be used to see which tissues are metabolically active. Iodine 131 is used to track thyroid function and structure.
What are the effects of high-level radiation?
It can destroy cells. It can also damage dna, which can cause cancer. Careful usage can sterilize products, and targeted isotopes can destroy specific cancer cells.