Biology

any substance which has mass and occupies space

a substance that cannot be broken down by chemical means. Elements are defined by the number of protons they possess.

• The basic unit of a chemical element.
• A typical atom consists of a nucleus of protons and neutrons with electrons circling this nucleus.

The central and most important part of an object, movement, or group, forming the basis for its activity and growth.

The positively charged central core of an atom, containing most of its mass.

An orbital can contain two electrons with paired spins and is often associated with a specific region of an atom.

The region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital.

• A stable subatomic particle occurring in all atomic nuclei, with a
• POSITIVE electric charge equal in magnitude to that of an electron.

A subatomic particle of about the same mass as a proton but ha NO Electrical Charge, present in all atomic nuclei except those of ordinary hydrogen

A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity

The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

• The mass of an atom of a chemical element expressed in atomic mass units.
• It is approximately equivalent to the number of protons and neutrons in the atomor to the average number allowing for the relative abundances of different isotopes

• Each of two or more forms of the same element that contain equal numbersof protons but different numbers of neutrons in their nuclei.
• Differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element

an electrical force linking atoms.

• A group of atoms bonded together, representing the smallest fundamental
• unit of a chemical compound that can take part in a chemical reaction

a chemical species that is formed when two or more atoms join together chemically, with covalent or ionic bonds.

• structure of a substance.
• Bonds break and new bonds form

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains an electron to form a negative ion.

a chemical bond that involves sharing a pair of electrons between atoms in a molecule.

electrons are shared equally between the two atoms.

Unequal sharing of electrons

A weak bond between two molecules.

Having an affinity for water; attracted to water

Tending to repel or fail to mix with water; repelled or fear of water.

• when added to water releases hydrogen ions (H+), also called protons.
• Acids are electron pair acceptors.

• When added to water releases hydroxide (OH-) ions.
• A substance that can Donate a pair of electrons to form a covalent bond.

a measure of acidity and alkalinity of a solution that is a number on a scale

Sodium chloride (NaCl), a white crystalline substance that gives seawater its characteristic taste

stored energy, is the ability of a system to do work due to its position or internal structure

energy of motion

The degree or intensity of heat present in a substance or object, esp. as expressed according to a comparative scale and shown by a thermometer or perceived by touch

any compound of carbon and another element or a radical