Structure + Bonding Flashcards
what is an atom?
the smallest part of an element that can exist, composed of protons, neutrons and electrons
what is an element?
a substance that only contains one type of atom
what is a compound?
contains 2 or more elements which are chemically combined in fixed proportions held together by chemical bonds
how are elements separated in compounds?
by electrolysis or chemical reactions
what are reactants?
the substances that react. usually on the left side of an equation
what are products?
the new substances that are formed. usually on the right side of an equation
what are mixtures?
consist of two or more elements or compounds which are not chemically bonded together
what is filtration?
used to separate soluble solids from insoluble solids
what is crystallisation?
used to obtain a soluble solid from a solution, such as salt from salt water
what is simple distillation?
technique used to separate a substance from a mixture due to a difference in boiling points of the components in a mixture
what is the relative mass of protons and neutrons?
1
what is the relative mass of an electron?
0
what charge does proton have?
+1 or positive
what charge does a neutron have?
0
what charge does an electron have?
-1 or negative
whats the radius of an atom?
0.1nm or 1 x 10^-10m
what is the relationship between the number of protons and electrons?
they are equal so they cancel out, making the atom neutral
what is an ion?
when the atom loses or gains electrons, making it charged
what makes an ion negative?
when there is more electrons than protons (non metals)
what makes an ion positive?
when there is more protons than electrons (metals)
what is an elemental symbol?
the one or two letter symbol that represents the element in a periodic table
what does the atomic number tell us? (bottom left number)
the number of protons and electrons the element has
what does the mass number tell us? (top left number)
total number of protons and neutrons in that atom
whats the radius of the nucleus of an atom?
1 x 10^-14
how would you calculate the number of neutrons in an atom?
mass number subtract atomic number
what determines an element?
the number of protons determines what type of atom it is. for example, 1 proton makes hydrogen
what is an isotope?
same number of protons but a different number of neutrons so they have the same atomic number but different mass numbers
how do you calculate relative atomic mass?
relative atomic mass = (the sum of isotope abundance and isotope mass number) / sum of abundance of all isotopes
what is relative atomic mass?
as many elements can exist as a number of different isotopes, relative atomic mass is used instead of mass number when referring to the element as a whole. this is an average mass taking into account the different masses and abundance (amount) of all isotopes
what is ionic bonding?
a compound made up of metal and non metal consists of ions. the metal atoms lose electrons to form positive ions and the non metal atoms gain electrons to form negative ions. the opposite charges mean that they are strongly attracted to each other and have strong electrostatic forces