Chapter 2: The Chemical Context Flashcards
What is an element?
A substance that cannot be broken down to other substances.
What is a compound?
A substance consisting of two or more different elements.
What is an essential element?
A chemical element required for an organism to survive, grow, and reproduce
What four elements make up 96% of living matter?
Carbon, Hydrogen, Oxygen, and Nitrogen (CHON)
What elements account for the makeup of the other 4% of living matter?
Calcium, Phosphorus, Potassium, Sulfur (CPPS)
What are trace elements?
An element indispensable for life but required in extremely minute amounts. ex. iron, iodine
What is an atom?
The smallest unit of matter
What are neutrons?
Subatomic particle having no electrical charge
What are protons?
Subatomic particle with a single positive electrical charge
What are electrons?
Subatomic particle with a single negative electrical charge.
What is atomic number?
The number of protons in the nucleus of an atom.
What is mass number?
The total number of protons and neutrons in an atom’s nucleus.
What is atomic mass?
The total mass of an atom
How do you deduce the number of neutrons an atom has?
mass number - atomic number
What is an isotope?
One of several atomic forms of an element, each with the same number of protons but a different number of neutrons.
What is potential energy?
The energy that matter possesses as a result of its location or spatial arrangement.
How many electrons can the first electron shell hold?
2
How many electrons can the second electron shell hold?
8
How many electrons can the third electron shell hold?
8
What are the rows of a periodic table called?
Periods
What are valence electrons?
Electron(s) in the outermost electron shell
What is a valence shell?
The outermost energy shell of an atom; contains valence electrons
True or false; an atom with a completed valence shell is reactive.
False; an atom with a completed valence shell is UNreactive.
What does inert mean?
Chemically unreactive.
What is a chemical bond?
An attraction between two atoms, resulting from sharing of outer-shell electrons
What are the strongest kinds of chemical bonds?
Covalent and Ionic
What is a covalent bond?
A type of bond in which two atoms share one or more pairs of valence electrons.
What is a molecule?
Two or more atoms held together by covalent bonds.
What is a double covalent bond?
Sharing of two pairs of valence electrons by two atoms
What is a single covalent bond?
Sharing of a pair of valence electrons by two atoms
What is valence?
The bonding capacity of a given atom.
What is the valence of hydrogen?
1
What is the valence of oxygen?
2
What is the valence of nitrogen?
3
What is the valence of carbon?
4
What is electronegativity?
The attraction of a given atom for the electrons of a covalent bond.
What is a nonpolar covalent bond?
Type of covalent bond in which electrons are shared equally between two atoms
What is a polar covalent bond?
A covalent bond between atoms that differ in electronegativity.
What is an ionic bond?
A chemical bond resulting from the attraction between oppositely charged ions (cation and anion)
What is a hydrogen bond?
A type of weak chemical bond that is formed when a slightly positive hydrogen atom is attracted to a slightly negative atom.
