Chemical Basis of Life Flashcards
Nucleus
is made up of a proton, a positive charge, and a neutron, which has no charge
Electrons
negative charge
What does each shell/energy level have?
Anything ≥2 electrons, protons equal to electrons
Outermost shell/energy level
valence shell and it contains the chemically reactive electrons.
Matter
anything that occupies space & has mass
Atom
the smallest unit of matter that retains the properties of an element
Element
A substance that cannot be broken down into other substances (normally)
Molecule
group of ≥2 atoms bonded together. e.g h2
Compound
molecule containing ≥2 elements in a fixed ratio e.g. CHO, NaCL, H20
Mixture
≥2 elements mixed in varying ratios. Bonds may not form. e.g. sucrose and calcium
Solution
A liquid homogenous mixture of ≥2 elements
What is a solution made of?
Solvent, dissolving agent. Solute, the substance that is dissolved
Atomic number
Number of protons
Mass number(atomic mass)
sum of protons and neutrons
Radioactive Isotope(radioisotope)
An isotope w/ an unstable nucleus, decays, & emits enrgy & particles(+,0,-)
Isotope
A variant form of an element. contains a variant number of neutrons e.g. 12^C, 13^C, 14^C
Ion
An atom that has gained or lost an electron, therefore has a net positive or negative charge. Na+, Cl-
Octet rule(ruleof eights)
atoms are reactive until they have 8 electrons in their valence shell, form bonds
What will not form bonds?
atoms with their valence shells filled making them stable/inert
Ionic Bonds
Electrons are accepted or donated. the product is called an ion.
What are atoms that give up an electron called
Cations and have a net positive charge
What a atoms that accept an electron called
Anions and have a net negative charge
Covalent bonds
electron pairs are shared e.g. H2= H-H (1 pair shared), O2= O=O (2 pairs shared), N2= N ☰ N
Nonpolar
both atoms exert equal pull on the shared electrons e.g. H2
