Chemistry 2a Flashcards
What is the atomic number of an atom?
The number of protons and electrons.
What is an isotope?
An atom with an irregular number of neutrons.
What is a compound?
2 or more atoms that are chemically bonded.
What type of atoms are included in an ionic bond?
Metals and non-metals.
Which two groups will form ionic bonds the easiest? Why?
Groups 1 & 7, they only have 1/need 1 electron on the outer shell.
If an element gains 2 electrons, what charge will be on the atom?
2-
What are the ions formed in magnesium oxide?
(Mg)2+ and (O)2- The charges formed in ionic bonds are on the chemistry data sheet.
Why do metals conduct heat & electricity so well?
As well as the vibrating, positively charged atoms, there are free electrons that collide with atoms passing on kinetic energy an heat.
Why are pure metals often weak and brittle?
Because of their regular shape, rows of atoms can easily slide over each other.
What are the properties of diamond?
The hardest substance on earth. Made entirely of carbon, each carbon atom has 4 bonds, forming a lattice.
What are smart materials?
Materials that change behaviour depending on conditions.
What are nanoparticles?
Tiny, tiny particles that have uses such as sun tan cream and in making self-cleaning windows.
Give the properties of a thermosoftening polymer
Individual tangled polymer chains that easily slide over each other when heat is applied. The intermolecular forces are very weak indeed.
Give the properties of a thermosetting polymer
These are polymer chains with strong cross-links that are VERY hard to break. They don’t soften when heated, just char at unbelievably high temperatures.
What is the relative atomic mass (Ar) of an element?
The atomic number.
