Question | Answer |
materials scientist | someone who studies the characteristics and uses of various materials, such as metals, ceramics, and plastics |
materials engineer | someone who uses the characteristics of existing materials to design new products |
Trade-off | An exchange of one thing in return for another. Giving up something that is a benefit or an advantage, in exchange for something that may be more desirable. Trade-offs always involve balancing benefits against risks. |
atom | The basic structural unit of matter; the smallest particle of an element that can enter into a reaction. |
atomic mass | The average mass of atoms of an element, it's also known as atomic weight. |
element | A collection of atoms of one type that cannot be decomposed into any simpler units except by spontaneously changing into other units by radioactive processes. Oxygen, hydrogen, iron, and carbon are example of elements. |
family (of elements) | A grouping of elements based on similar chemical properties. Families are generally arranged by columns in the periodic table. |
metal | Elements with following properties: high melting temperatures, high density, hard, high thermal conductivity and high electrical conductivity |
Periodic Table of Elements | An arrangement of the elements according to their atomic numbers so that elements with similar properties are in the same column. In 1869, Dmitri I. Mendeleev designed the first periodic table to show the similarities and differences of the elements. |
Compound | A combination of atoms of two or more different elements in a set ratio |
Molecule | Two or more atoms joined together chemically (can be the same element) |
Chemical Formula | A shorthand notation to describe elements and compounds and their reactions. Ex. HCl + NaOH → H2O + NaCl |
Non-metal | Elements with following properties: low melting temperature, low density, soft, low thermal conductivity and low electrical conductivity |
Semi-metal (metalloid) | Elements with properties of both metals and non-metals |
Noble Gases | Gases in the family on the periodic table that rarely react with other elements |
Atomic Number | The number of protons in the nucleus of an atom |
Isotope | Elements with different number of neutrons |
Electron | Negatively charged particle that moves around the nucleus of an atom |
Proton | Positively charged particle in the nucleus of an atom |
Neutron | Particles in the nucleus of an atom with no charge |
Mass Number | The total number of protons and neutrons in the nucleus. The mass number is the atomic mass rounded to the nearest whole number |
Chemical Bond | The electrical attraction between two different atoms (elements) that forms a molecule (compound) |