Isotopes
What is the hyphen notation for Carbon with an atomic mass of 12 and atomic number 6?
C-12
What defines an atom as positive or negative?
An atom is an ion if it has gained or lost electrons, resulting in a net charge.
List the three types of subatomic particles.
neutron, protons, electrons
If Oxygen-16 has an atomic mass of 15.96 amu with an abundance of 85% and Oxygen-17 has an atomic mass of 16.02 amu with an abundance of 15% what's the average atomic mass?
Calculated as: (15.96 x .85) +(16.02 x .15) = 15.97 amu
Who discovered the neutron?
James Chadwick; he conducted experiments that led to the identification of the neutron.
How many neutrons are in the isotope 14C
8 neutrons (since 14 - 6 = 8)
What subatomic particle makes an element an ion (changes the charge)?
Electron
What charge do protons carry?
Positive
If Neon has a mass of 20.1 amu at an abundance of 90% and Ne-22 has a mass of 22.2 amu... what is the average atomic mass of Neon?
20.31 amu
(calculated as (20.1 * 0.9) + (22.2 * 0.1))
What did Rutherford discover about atomic structure?
He discovered the nucleus and proposed that atoms are mostly empty space.
Write the nuclear notation for Helium with atomic number 2 and atomic mass 4.
24He
How does a neutral atom become a positive (+) ion?
AND
How does a neutral atom become a negative (-) ion?
It loses electrons
AND
It gains electrons
Where are protons and neutrons found?
The nucleus
How do you convert grams to moles using the periodic table?
Divide the mass given in grams by the molar mass of the substance.
What was Millikan's contribution to atomic theory?
He measured the charge of the electron through the oil drop experiment.
If an isotope has an atomic number of 11 and an atomic mass of 23, how many neutrons does it have?
12 neutrons (23 - 11 = 12)
An atom that has 4 protons and 4 neutrons, and 5 electrons would have a nuclear notation of?
84Be-1
Why is the electron cloud not included in the atomic mass?
Electrons have negligible mass compared to protons and neutrons.
How many atoms are in 16.5 moles of Fe?
9.93×1024 atoms of Fe
(calculated as 16.5 moles x (6.02×1023atoms/1 mol)
Describe Dalton's atomic theory as it relates to elements.
Dalton proposed that each element is made of atoms, he gave us the 5 statements known as Atomic Theory
Describe the difference between isotopes of an element.
Isotopes of an element have the same number of protons but different numbers of neutrons, resulting in different atomic masses.
An atom with 7 electrons, an atomic number of 9, and a mass number of 18 would be written in nuclear notation as?
189F+2
What particle changes to make an isotope of a particular element?
Neutron
How many moles are in 39.3 g of As?
0.5 moles of As
Calculated by: 39.3 g x (1 mol/74.922g)
What did Mendeleev contribute to chemistry?
He created the periodic table and arranged elements by atomic mass and properties, predicting the existence of undiscovered elements.