3. Atomic Structure

proton relative charge

+1

neutron relative charge

0

electron relative charge

-1

relative mass of proton

1

relative mass of neutron

1

relative mass of electron

1/1840

fill in blanks

electron shell nucleus protons (p) neutrons (n) electron (e)

for first _ elements, valence shell can only hold _ electrons. After that, valence shell can hold ___ electrons

20 8 18

atoms are _________ _________ (no. of ________ = no. of __________)

electrically neutral protons electrons

what is A? What is Z?

nucleon no., proton no.

what are isotopes? (isotopes are _____ of the _____ element with the _______ number of protons, but ___________ number of neutrons.)

isotopes are atoms of the same element with the same number of protons, but different number of neutrons

isotopes have _______ __________ properties (due to ______ number of __________)

same chemical same electrons

isotopes have _______ __________ ___________ properties (due to ______ number of __________)

slightly different physical different neutrons

ions' no. of protons and no. of electrons are ________

different

what makes an ion positive (cation)? (______ protons than electrons)

more protons than electrons

what makes an ion negative (anion)? (______ protons than electrons)

less protons than electrons

defenition of relative atomic mass Ar (the _________ mass of ____ _____ of an element compared to /_ the mass of an _____ of carbon-12)

average one atom 1/12 atom

Ar is to ____ decimal place

one

For elements to have similar chemical properties, they are in the same _______ and have the _____ __________ of _______ ______

group same number valence electrons

electronic structure of atom: ________ of atom and ________ of _________

identity number electrons

isoelectronic: have the _____ ______ ________ of _______

same total number electrons