Atoms Flashcards
Alpha Particle charge
Positive
Where are the Electrons located?
Around the nucleus, in the electron cloud
Atoms are mostly __________
Empty space
If helium has the atomic# of 3, how many protons does it have?
3 protons
What does the Atomic # stand for?
of protons
If helium has 3 protons, how many electrons does it have?
3 electrons
What is the decimal at the botom of the letter stand for?
The average mass of all the isotopes of the element
What is the decimal at the botom of the letter called?
Atomic mass
What is the mass #?
sum of protons and electrons
What was the Gold foil for?
A thin layer of atoms
what did Rutherford’s expirement suggest?
That Atoms were mostly space, but did have solid particles, like the nucleus.
What are the energy levels for electrons?
2, 8, and 8
how much does 1 neutron weigh?
1 a.m.u
How much does 1 electon weigh?
almo.st nothing
how much does 1 proton weigh?
1 A.M.U
How much does the nucleus weigh in percent vs the rest of the atom?
The nucleus is tiny, but ver very heavy. It takes up 99% of the atoms weigt.
If H has an atomic mass of 8. 066, and an atomic number of 3, then how many neutrons does it have?
5 neutrons.
What is the Isotope of an element?
2 atoms with othe same # of protons but with a diferent amount of neutrons
If you had carbon 12 and Carbon 14, whats different about them?
They are Isotopes. Carbon 12 has 12 nuclei, but carbon 14 has 14 Nuclei
Why is the atomic mass a decimal?
Because the atomic mass is the average mass of all isotopes.
How many electrons does it take to equal 1 amu?
2,000 electrons = 1 A.M.U
How is an element Identified?
By the number of protons. 2 atoms of the same element mus have the same # of protons, but the nuetron # can vary, thus creating Isotopes.
Isotopes are identified by _____
the atomic mass
The atomic # of Argon is 18. How many protons does it have?
18
Scandium has 21 protons. what is its atomic #?
21
The atomic # of copper is 29. It’s mass number is 64. How protons / Neutrons does it have?
20 protons, and 35 neutrons.
if Choromine’s mass # is 52, and it has 24 protons, how many nuetrons does it have?
28
between mass # and atomic #, which one talks of only one atom?
mass number.
