Chapter 2 Chemistry Of Life Flashcards
What is a element?
It is a pure substance that cannot be broken down by chemical means into other substances.
What is matter?
Matter is any material that takes up space, such as organisms, rocks, and the oceans
Compare bulk and trace elements?
Bulk elements make up the vast majority of every living cell such as, carbon, hydrogen, oxygen, and nitrogen. The trace elements they are required in small amounts.
What is an atom?
An atom is the smallest possible piece of an element that retains the characteristics of the element.
What is a ion?
An ion is an atom that has gained or lost elements and therefore has a net negative or positive charge.
What is a mass number?
A mass number is the total number of protons and neutrons in its nucleus.
What is a isotope?
An isotope is any different forms of a single element.
How are isotopes used in science?
Because radioactive isotopes have the same chemical properties as stable isotopes, they have a variety of uses in science such as killing disease-causing organisms, they are used as tracers, they are used for radioactive tracing, and they are used in cancer therapy.
Compare mass number and atomic number?
The atomic number is the number of protons in the nucleus and the mass number is the total number of protons and neutrons in its nucleus.
What links atoms?
Molecules links atoms
Compare molecule and compound.
A molecule is two or more chemically joined atoms. Some atoms are diatomic which means they consist of two atoms of the same element. A compound is a molecule composed of two or more different elements.
What is a energy shell?
A energy shell is a group of orbitals that share the same level.
What is a valence shell?
A valence shell is its outermost occupied energy shell.
What is a chemical bond?
A chemical bond is an attractive force that holds atoms together.
How are covalent bonds formed ?
Covalent bonds form when two atoms share electrons. The shared electrons travel around both nuclei, strongly connecting atoms together.
What is electronegativity?
Electronegativity is a measure of an atom’s ability to attract electrons.
Compare polar and nonpolar covalent bonds?
Nonpolar is a bipartisan union in which both atoms exert approximately equal pull on their shared electrons. A polar covalent bond in contrast is a lopsided union in which one nucleus exerts a much stronger pull on the shared electrons than does the other nucleus.
What is a hydrogen bond?
An atom with a partial negative charge attracts an atom with a partial positive charge.
How are hydrogen bonds formed?
Hydrogen bonds form between adjacent molecules or different parts of a large molecule.