An element becomes a cation when it has more ______ than ________.
Protons than electrons
What has a highest electronegativity?
Calcium (Ca)
Tin (Sn)
Aluminum (Al)
Aluminum (Al)
Who devised the Plum Pudding Model of the atom, where negatively charged electrons are posed in a negatively charged space?
J.J. Thomson
How many significant figures does the following number have?
0.000000002470
Carbon - 13 has one more of what than Carbon-12?
What is a neutron?
True or False: Anions and Cations cannot have negative charges greater than (-1) and positive charges greater than (+1).
False.
True or False: If you change the number of neutrons in an atom the element changes?
False
Which two tenets of Dalton's Five Tenets can we only partially accept.
What are Tenets One and Two?
How many significant figures does this number have?
7.02860 x 1020
6
Copper-63 has how many neutrons?
34
False.
What number on the periodic table tells you the number of electrons in a naturally occurring atom of an element?
The atomic number
The Greeks believed that there were an infinite number of particle types based on the infinite amount of materials in the world, but they had some disagreements. What were two reasons why Aristotle disagreed with Leucippus and Democritus?
Aristotle believed atoms were infinitely divisible and could be categorized by the classical elements.
What do significant figures help us to protect in our calculations?
The certainty of our measurements.
The relative abundance and masses of different isotopes can be measured using what instrument?
A mass spectrometer (mass spectroscopy)
If an atom has 16 protons, 18 electrons, and 18 neutrons, is it an atom, a cation, or an anion?
If you change the number of protons in an atom what do you get?
What is a different element?
Milikan calculated the mass of an electron from the experimental data of J.J. Thomson and the data of his oil drop experiement. What is the mass of an electron that he calculated?
what is 9.11 x 10^-31 kg?
What should never change after performing significant figure approximations?
The scale of the numeric value (809380, should still be on the scale of 100,000 after our calculations).
How many protons, neutrons, and electrons does Lead-180 have?
82 protons, 82 electrons, 98 neutrons
What instrument was used to discover that electrons had a negative charge?
A cathode ray tube
What is the common name for He2+
What is an alpha particle?
Who was the first scientist to include all three subatomic particles in his model of the atom?
Chadwick
What is the rule for addition and subtraction?
What is round to the place of least certainty?
Galium has two naturally occurring isotopes. The mass of gallium-69 is 68.9256 u and it is 60.108% abundant. The mass of gallium-71 is 70.9247 u and it is 39.892% abundant.
Calculate the atomic mass of Gallium.
am = (68.9256 u x 0.60108) + (70.9247 x 0.39892)
= 41.430 + 28.293
= 69.7231 u