Chemical Basis of Life Flashcards
What is an element?
A substance that cannot be broken down into other substances by ordinary chemical means
Which 4 elements make up 96% of the weight of the human body?
Hydrogen, Oxygen, Carbon and Nitrogen
What is a compound?
A substance consisting of 2 or more different elements combined in a fixed ratio
What is an atom?
The smallest unit of matter that still retains the properties of an element
What are the 3 types of subatomic particles?
Proton, electron and neutron
What are the different charges of each type of subatomic particle?
Proton - a single positive charge
Neutron - no charge
Electron - a single negative charge
What is the core of an atom called?
Nucleus
In regards to chemistry, what is the nucleus?
It is the core of an atom
What do you call a substance that cannot be broken down into other substances by ordinary chemical means
An element
What do you call a substance consisting of 2 or more different elements combined in a fixed ratio
A compound
What is the atomic number of an element?
The number of protons in an atom of that element
What is the mass number of an element?
The sum of the protons and neutrons in one atom of the element being considered
What do you call the sum of the protons and neutrons in one atom of a specified element?
The mass number
All atoms of an element have the same _____ number
Atomic
If all atoms of an element have the same ____, then they all have the same number of _____ in their nucleus.
a) atomic number, protons
b) mass number, neutrons
The different _____ of an element have the same numbers of protons and electrons, but they have a different numbers of neutrons.
isotopes
What is a radioisotope/radioactive isotope?
“any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays.”
What is an ion?
An ion is an atom or molecule with an electrical charge resulting from a gain or loss of one or more electrons
Define ionic bond
type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom. The atom that loses the electrons becomes a positively charged ion (cation), while the one that gains them becomes a negatively charged ion (anion).
Define covalent bond
the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons. A covalent bond forms when the bonded atoms have a lower total energy than that of widely separated atoms.
