These are easy
Particles that are found in the atomic nucleus are:
What are protons and neutrons
Which scientist is credited with discovering the charge of individual electrons?
Who is Millikan
How many neutrons does the most common isotope of hydrogen have?
What is 0 neutrons
How are isotopes of the same element similar?
What is having the same Atomic Number
Democritus believed that matter was made up of
Who was the first person to propose the
idea that matter was not infinitely
divisible?
Who is Democritus
The smallest particle of an element that
retains the properties of the element is
called an
What is an Atom
The atomic mass of an element is the
_____________ mass of the isotopes of
that element.
What is the weighted average mass
Atoms are mostly
What is empty space
Whe the protons and neutrons in the nucleus are added together, the result is the called the
What is the mass number
The number of protons in the nucleus of an
atom identifies the element and is known as
the element’s
What is the Atomic Number
Atoms with the same number of protons but
different numbers of neutrons are called
What are Isotopes
What is the densest region of an atom?
What is the Nucleus
An unknown element has 19 protons, 19
electrons, and 3 isotopes with 20, 21 and
22 neutrons. What is the element’s atomic
number?
What is 19
Who proposed the nuclear atomic model
Who is Ernest Rutherford
TRUE/FALSE
If False, give the right answer
The number of Neutrons in an atom is referred to as its atomic number?
What is False, its Protons and Neutrons
Radiation that originates from the cathode and travels to the anode of a cathode-ray tube.
What is a Cathode Ray
Write each isotope below in symbolic notation. Use the Periodic table to determine the atomic number of each isotope.
1. Neon-22
2. Helium-
3. Cesium-133
4. Uranium-234
1. 2210Ne
2. 42He
3. 13355Cs
4. 23492U
Isotope Number of Protons Number of Electrons Number of Neutrons Mass (amu)
P+ E- N Mass
Isotope 1 24 24 26 49.946
Isotope 2 24 24 28 51.941
Isotope 3 26 26 30 55.999
Isotope 4 24 24 29 52.941
Isotope 5 24 24 30 53.939
Isotope 6 26 26 31 56.969
Which of the isotopes listed are the same element? Explain your reasoning.
Isotopes 1, 2, 4, and 5 are the same element; they all have 24 protons. Isotopes 3 and 6 are another element; they both have 26 protons.
The Atomic Mass of an atom is usually not a whole number because it accounts for
What is both the relative abundance and the mass of each of the atoms isotopes.
Compare and Contrast each pair of related terms.
Mass number, atomic number
Comparison: Both pertain to atoms.
Contrast:The mass number is the sum of the protons and neutrons in the nucleus of a given atom. The atomic number is the number of protons found in the nucleus of every atom of that element
List the Symbol, Location, Relative Charge, Relative Mass for Proton, Neutron, Electron
Proton- P+, Nucleus, 1+, 1
Neutron- n0, Nucleus, 0, 1
Electron- e-, outside nucleus, 1-, 1/1840
How many neutrons, protons, and
electrons does
12454Xe have?
What is 70 neutrons, 54 protons, 54 electrons
Determine the number of protons, electrons, and neutrons for each isotope described below.
An isotope has 14 electrons and a mass number of 28.
An isotope has 21 neutrons and a mass of 40.
An isotope has atomic number 19 and a mass number 39.
1. Protons- 14 Neutrons- 14 Electrons- 14
2. Protons- 19 Neutrons- 21 Electrons- 19
3. Protons- 19 Neutrons- 20 Electrons- 19
Match each scientist below with his contribution to our understanding of the atom:
1. Atomic Theory of Matter
2. First proposed idea of Atoms
3. Gold foil experiment lead to discovery of the nucleus
4. Discovered the neutron
5. Discovered that each element has a unique amount of positive charge in its nucleus.
Scientists: John Dalton, Henry Mosely, Sir James Chadwick, J. J. Thomas, Ernest Rutherford, Democritus
1. John Dalton
2. Democritus
3. Ernest Rutherford
4. Sir James Chadwick
5. Henry Moseley