Some terms for test one

A compound made of 2 elements.

group of elements bonded together that behave as a single charged particle.

Positive charge Lose electrons Tend to be metals

negative charge tend to be non metals gain electrons

Metal + nonmetal Ionic bonds Transfer electrons from metal to nonmetal

Just non metals covalent bond shares electrons

When an atom or ion has the same number of electrons. Name 3 atoms or ions that are isoelectronic to Kr: Br1-, Rb+, Sr2+

the tendency of atoms to achieve a stable configuration with eight electrons in their outermost shell, known as the valence shell

metals: shiny good confuctor of heat malleble metalloids: shiny and dull mix of non metal and metal semi conductors nonmetals: brittle dull does not conduct heat

Group 3 elements to the staircase. multivalent metals are those that can lose different numbers of electrons when forming an ion and will therefore have more than one valence Exceptions: Zn2+, Cd2+, Ag1+

They are more reactive because it is easier to lose one electron than it is to lose 2 making it less stable and more reactive

alaki metals, alkaline earth metals, halogens, noble gases

alaki metals: reactive, 1 electron is outermost shell, metals alkaline earth metals: metals, very reactive but less than alaki metals, 2 electrons in outermost shell Halogens: very reactive, non-metals, 7 electrons in out shell, exsist as diatomic elements HOFbrNCl Noble gases: odorless, colourless, typicially non reactive, glow brightly, non metals, 8 valence electrons

ATOM: Protons = atomic number Neutrons = mass number – atomic number Electrons = protons (because neutral = no charge) ION: Protons = atomic number Neutrons = mass number – atomic number Electrons = atomic number – charge (if positive ion) or protons + charge (if negative ion) IF A NEGATIVE CHARGE, ADD. POSITIVE CHARGE, SUBTRACT

Two metals do not form a compound because they both want to lose electrons, so no electron transfer happens

ammonia

Nitric oxide

methane