Atomic Structure Flashcards
What are the 2 observations we made during the gold foil experiment?
1-The beam of alpha particles passed through the gold sheet.
2-The alpha particles scattered.
Explain why the alpha particles passed through the gold sheet undeviated.
1-Most of the atom is empty space.
2-The nucleus is tiny.
Explain why some alpha particles got deviated with an angle greater than 90?
1-There is a heavy nucleus.
2-The nucleus is tiny.
3-The nucleus is positively charged.
Explain why some alpha particles got deviated with angle less than 90?
The nucleus is positively charged.
What is the atom made of?
protons (+)
neutrons(no charge)
electrons(-)
what is the nucleon number?
number of protons and neutrons in the nucleus.
what are the masses of every sub-atomic particle?
protons(1)
neutrons(1)
electrons(1/1840)
positive ion
when an atom loses electrons.
negative ion
when atom gain electrons.
why is the atom neutral?
The number of positive protons are equal of the number of negative electrons.
atomic number
number of protons in an atom. (if changed the whole element change)
mass number(atomic mass)
number of protons+ neutrons in the nucleus.
number of neutrons
mass number-atomic number
Isotopes
Atoms of the element with the same number of protons and different number of neutrons.
what happens when an isotope is unstable?
it emits radiations until it achieves stability.
