chap2, form 4 Flashcards
definition of matter
Something that has mass or occupies space
matter is divided into 2. name it
elements and compounds
definition of isotope
Atoms of the same element with different no of neutrons and same no of protons
what are the 3 subatomic particles
proton, neutron, electron
charge, relative mass of proton
+1, 1
charge, relative mass of electron
-1, 1/1840
charge, relative mass of neutron
neutral, 1
acronym of chemists who found structure of atom
JJENJ
John dalton found
atom
J.J Thomson found
electron and proton
Ernest rutherford found
nucleus, and that electrons orbit around it
Neils bohr found
shell
James Chadwick found
neutron
Why does the temperature remain constant at melting/boiling/freezing point?
Heat energy absorbed/released is used to break forces of attraction / pull them closer
as heat energy ___, kinetic energy ___
increases, increases
formula to find RAM of isotopes
[%]isotope x mass + [%]isotope x mass over 100
use of cobalt-60
clue: medical
radiotherapy, cancer
use of iodine-131
clue: medical
treat thyroid disorders
use of phosphorus-32
clue: agriculture
plant metabolism
use of uranium-235
generate electricity
use of carbon-14
carbon dating
use of lead-210
determine age of rock, earth
use of hydrogen-3
treat sewage and liquid waste
use of sodium-24
detect leakage in underground pipes
electronic structure of atom has these 2 features
label nucleus with atom
electron arrangement
atomic structure of atom has this feature
in nucleus, write number of proton and neutron
limit for 3rd shell of electrons
18
Why is a water bath used?
To ensure even heating of substance.
Why is naphthalene not heated directly using Bunsen Burner?
To avoid direct heating which can produce poisonous and flammable vapour gas
Why is naphthalene stirred continuously, and boiling tube cooled inside a conical flask?
To ensure that an even cooling process is carried out
