Atomic structure Flashcards
how many electrons are in the second shell of an atom?
8
how many electrons are in the third shell of an atom?
18
how many electrons are in the fourth shell of an atom?
32
what is ionic bonding?
a metal + non-metal bonding together
what is electrovalent bonding?
a metal + a metal bonding together
what happens when you heat a small piece of sodium on a defragerating spoon and plunge into chlorine?
combining the silver shiny metal (sodium) with the green gas (chlorine) is quite a violent reaction with a white taken and forms a white solid (salt) sodium chloride
how many electrons are in the first shell of an atom?
2
The difference between an element and a compound
elements are mad of atoms with the same number of protons in the nucleus whereas compounds are two or more different elements chemically bonded together in fixed proportions by mass
distinguish the term between atom and an ion
an atom has an equal number of protons and electrons as it is neutral whereas ions have a different amount
what is a positive charge of a particle called?
cation
what is a positively charged particle called?
anion
what is a particle called when it is neutral?
atom
what is a particle called when negatively charged?
electron
what is a positively charged ion called?
protons
when two solutions mix together and form a solid, what is the solid called?
a precipitate
what is the definition of a covalent bond?
it is the electrostatic force of attraction that two nuclei have for a shared pair of electrons
what is ammonia?
NH3
what does the atomic number show us?
The amount of protons
what does the mass number of an atom tell us?
how many neutrons there are + protons
how do you work out the radiuS of an atom?
1 x 10to the 10- (m)
how do you work out the radius of the nucleus?
1 x 10 to the -15 (m)
wht do the protons equal?
electrons
How do you work out the charge of an atom?
protons - electrons
what is the definition of an isotope?
Isotopes are the atoms of the same element which differ from each other by having differing numbers of neutrons in the nucleus (as the atoms are the same element, isotopes of the element all have the same number of protons in the nucleus)
a b
C
d
What does B =?
the charge
how do you know if isotopes are radioactive
The nucleus is unstable and could split apart
when a compound has ionic bonding, decried it’s structure.
it will have structures made up of positive and negative ions- oppositely charged ions are held together by electrostatic forces in a giant lattice…. SOLID STATE ions are arranged as giant ionic crystals aswell as in the lattice LIQUID STATE ions are close but in an irregular formation GASEOUS STATE ions are far apart moving freely
what is the structure of sodium chloride?
a giant 3D cubic lattice
Electrostatic forces are strong
they have strong attraction between the oppositely charged ions, these require a lot of energy to break them… with ionic compounds it will take a lot of heat to melt them (why compounds have higher melting points)
what are the differences between ionic substances and covalent substances?
ionic substances usually dissolve in water but not in non-polar solvents- covalent is the other way round.
Ionic substances conduct electricity in water and when melted but not when it’s in solid state- covalent bonds don’t