atom element and compound (Jack) (elements compound and mixture (An…
atom element and compound (Jack)
physical and chemical change
Physical changes — involve a change in one or more physical properties, but
in the fundamental components that make up the substance.
The most common physical changes are changes of state: solid ↔ liquid ↔ gas.
involve a in the fundamental components of the substance: a given substance changes into a different substance or substances.Chemical changes are called
elements compound and mixture
An element contains only one kind of atom.
A compound is made of atoms different kind s ,bounded together
Atoms are the smallest particles of matter, that we cannot break down
further by chemical means.
A mixture contains different substances that are not bonded
ion and ionic bound
An atom becomes an ion when it loses or gains electrons.An ion is a charge particle. It is charged because it has an unequal number of protons and electrons.
molecule and covalent bounds
both diamond and and graphite are made only of carbon so they are allot ropes two from of the same element
diamond strong convalent bonds and 1 携带4个 it properties is very hard and have high melting point(strong bonds between carbon atom ) it can use cutting and drilling
graphite 1 to 3 slippery have weak force between layer easy to slide each other and also have conductivity is only form three bonds i=one is free (it can use lubricant and electrical conductor)
silica it is similar to diamond Silica, SiO2, occurs naturally as quartz main material is sand silica is a giant convalent 1个带2个
Each silicon atom bonds covalently to 4oxygen atoms. And each oxygen atom
bonds covalently to 2 silicon atoms.
atomic structure and the periodic table
a period is a horizontal raw in the period table it tell you the number of total electrons shells
a group is a vertical column.it tell the number of electrons in their outer shell the outer shell electron also call valence electrons
Noble gas electronic structures are very stable Other elements want to
achieve the full outer shell by gaining / losing or sharing electrons.
notation of atom
Protons and neutrons form the nucleus, so are called nucleon
The total number of protons and neutrons in an atom is called its
Nuclear number(or mass number).
All atoms of the same element contain the same number of protons, which means you can identify an atom by the number of protons in it.
Number of neutrons =A-Z.
In an atom, number of electrons = number of protons.
first shell have 2 second have 8 and third also have 8 when build new shell mean add 8 more electrons
The number of protons determines the type of element.Isotopes are atoms of the same elements which have the same protons number but a different neutrons number.