Pre-Test
Ions/Charges
Subatomic
Numbers
History of the Atom
100
This is the smallest part of an element.
What is an atom?
100
Objects with the same charge do this when they come close to each other.
What is repel?
100

Three subatomic particles.

What are protons, neutrons, and electrons?

100
The sum of protons and neutrons in the nucleus of an atom.
What is mass number?
100

Whose experiment that led to the discovery of the electron?

J. J. Thompson discovered the electron through the use of his Cathode Ray Tube experiment.

200
Neutrons are located outside of the nucleus. True or False?
False!
200
Objects with different charges do this when they come close to each other.
What is attract?
200
Located outside of the nucleus and have a negative charge.
What are electrons?
200
The number of protons in an atom of a certain element.
What is atomic number?
200

What two things did Rutherford's experiment tell us about the structure of the atom?

The atom is mostly empty space 

There is an incredibly small dense positive center

300
Electrons are located outside of the nucleus. True or False?
True!
300

What is an ion?  What are the two ways in which an ion can be made?

An ion is an element that has gained or lost electrons resulting in a positive or negative charge.  If the atom gained electrons it is called an anion, and if electrons are lost it is called a cation

300
Located inside of the nucleus and have a positive charge.
What are protons?
300
The atomic number of Oxygen.
What is 8?
300

When was the idea of an atom first developed?  Describe this theory.

Democritus was the first person to think about atoms in 400B.C.  He called them "atomos."  He believed that all matter was composed of atoms.

400

The half life of Carbon-14 is 10 years, if a 250 gram sample initially exists and decays to 7.8 grams, how many years have passed?

50 years
400
When an atom loses an electron it has this kind of electrical charge.
What is positive?
400
Atoms of different elements have different numbers of these.
What are protons?
400
The mass number of Potassium.
What is 39.098?
400

  1. Which of these statements would Dalton have agreed with?  

  2. Atoms are the smallest particles of matter.

  3. The mass of an iron atom is different from the mass of a copper atom.

  4. Every atom of silver is identical to every other atom of silver.

  5. A compound is composed of atoms of two or more different elements.

Dalton would have agreed with a) because of the belief that all matter is comprised of indivisible particles called atoms.

Dalton would have agreed with b) and c) because his postulate says that atoms of one element would differ from atoms of another element. 

500

What is the atomic mass of an element that has two isotopes. The mass of the first isotope is 45.34 amu and has a relative abundance of 58%. The other isotope has an atomic mass of 49.02 amu. 

Missing relative abundance is 42% 

Amu of element is 46.88

500

Using your periodic table what element has 56 protons and 54 electrons? 

79 protons and 79 electrons?


atomic mass of 35.45 amu and 18 electrons?

Make sure to include the ion charge if it is not neutral

Ba +2

Au

Cl-1

500
An atom with the same number of protons but different number of neutrons.
What is an isotope?
500
Mass number - atomic number = ______ __ ________.
What is the numer of neutrons?
500

What are the 3 subatomic particles?  Describe the differences between them in terms of their masses, charges, and place within the atom.

Protons - positively charged, 1 amu, in the nucleus

Neutrons - no charge, 1 amu*, in the nucleus 

Electrons - negatively charged, 1/1840 amu, organized into energy levels around the nucleus

*is a little heavier than a p+

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