Atomic structure and periodic table 1 Flashcards
What does the nucleus contain
protons and neutrons
What charge does the nucleus have
positive
what is the charge and mass of an electron
negatively charged and no mass
what is the charge and mass of a proton
positively charged and 1 mass
what is the charge and mass of a neutron
neutral charge and 1 mass
what happens to the equal charge when it is an ion
it changes depending on what is added to it
how do you calculate the number of neutrons
mass number - atomic number
what are isotopes
different forms of the same element which have the same amount of protons but a different amount of neutrons
what does the mass number contain
protons and neutrons
what does the atomic number contain
proton
calculation for relative atomic mass
sum of(isotope abundance*isotope mass number)/ sum of abundance of all isotopes
what are compounds
substances formed from two or more elements and are held together by chemical bonds
what is making bonds
involves atoms giving away, taking or sharing electrons
how a compound made from a metal and non metal works
the metal atoms lose electrons to form positive ions and the non metal gains electrons to form negative ions. This is called ionic bonding because the opposite ions are attracted to each other.
how a compound made from two non metals work
consist of molecules, each atom shares an electron with another atom. This is called convalent bonding
what are the properties of a compound compared to the original elements
totally different
What are mixtures
no chemical bond between the different parts of a mixture and can be separated by physical methods.
Examples of mixtures
Air, Crude oil
what are the properties of a mixture compared to the original elements
they are a mixture of each part
How were elements arranged in the 1800
scientists had no idea of the atomic structure and could only measure relative atomic mass and so elements were in order of atomic mass.
How did Dmitri mendeleev change the periodic table. 1869
he made the periodic table in order of atomic mass but swapped them if the properties were similar. He left gaps in the table to make sure elements with similar properties stayed in the same groups and some were undiscovered elements. The elements were discovered and supported his theory.
how are elements with similar properties layed out on the periodic table
in columns
what does the group of the periodic table say
it tells you how many electrons are in the outer shell except for group 0
why do metals find it easy to form positive ions
metals to the left don’t have many electrons and metals at the bottom have electrons far away fro the nucleus meaning not much energy is needed to remove electrons making them form positive ions.
why do non metals find it easier to form negative ions
they have lots of electrons to remove or the outer electrons are close to the center meaning they have a strong connection. Which means it is easier to gain electrons to form negative ions
physical properties of metals
strong, malleable, high melting and boiling points, conducting heat and electricity, ductile
physical properties of non metals
dull looking, brittle low density, not good at conducting
special properties of transition metals
can have more than one ion
ions are often colored
make good catalysts
why are alkali metals so reactive
only contain one electron it the outer shell
properties of alkali
soft, low density, reactive
what happens as you go down the alkali column
increasing reactivity(electron is further away from center) lower melting and boiling points higher relative atomic mass
what kind of ion and bond does an alkali have
+1 ions and have ionic bonding
equation of alkali with water =
alkali hydroxide + hydrogen
equation of alkali with chlorine =
alkali chloride
reaction with oxygen alkali
form metal oxides
how are alkalis different to transition metals
more reactive
less dense, string and hard
lower boiling points
colour of Flourine gas
yellow/poisonous
colour of chlorine gas
dense green/poisonous
colour of bromine gas
red-brown/poisonous
colour of iodine
purple vapour or dark gray solid/poisonous
what happens as you go down the halogen group
less reactive
higher melting and boiling points
higher relative atomic masses
covalent bonding of halogens
share electrons with other non metals and when they react have simple molecular structures
ionic bounds of halogens
from 1- ions called halides when they bond with metals.
the compounds that form are ionic structures
what happens when more reactive halogens react with less reactive ones
the more reactive one displaces the less reactive and the salt
what happens when chlorine reacts with bromine
bromine is kicked from the solution
what is group 0
noble gases
why are noble gases unreactive
they have eight electrons making there outer shell full, making them inert
what does inert mean
unreactive
properties of noble gases
colorless at room temp
non flammable
what happends as you move down the noble gas group
boiling points increase
why do noble gases increase in boiling point
an increase in the number of electrons in each atom leading to greater intermolecular forces between each one
