Science Quiz #2 Flashcards
What is all matter made out of?
All matter is made out of atoms.
Has Atoms ever been seen?
False, Atoms have yet to be seen.
Who was the first person to propose an idea of matter?
John Dalton was the first person to propose an Idea of matter. He believed that atoms were solid, indestructible units.
Who disproved the idea that an Atom was the smallest particle?
Sir Joseph John Thompson disproved that an atom was the smallest particle due to his discovery of a subatomic particle.
Who revised Thomson’s model?
Ernest Rutherford revised Thompsons model.
What did Ernest Rutherford discover?
He discovered that atoms have a heavy nucleus.
Who discovered the existence of neutral subatomic particles. (AKA NEUTRONS)
While under Ernest Rutherford, James Chadwick proved the existence of subatomic particles. He named it “neutrons”
Who proposed the planetary model?
Niels Bohr proposed the planetary model.
M C
X
N
What does X mean?
It means the element symbol.
M C
X
N
What does N mean?
N means atomic number.
M C
X
N
What does M mean?
M means atomic mass.
M C
X
N
What does C mean?
C means net charge.
How do you get the atomic number?
To get the atomic number, you must get the amount of protons.
How to get Atomic Mass?
To get the atomic mass you must add the amount of protons and neutrons.
How do you get the Net Charge?
Protons = Positive
Electrons = Negative
Protons: 3
Electrons 2
3-2 = 1
The net charge would be 1.
Define what a period is.
A period is a row of elements whose properties change gradually and predictably.
Define an atomic number.
Refers to the number of protons which is equal to the number of electrons in a neutral atom.
What is the atomic radius?
The atomic radius is the measure of the size of an atom.
What is ionization energy?
The energy required to remove an electron from a gaseous molecule or atom and convert it to an ionization energy. It is expressed in joules or in electron volts.
What is Electron Affinity?
The energy released by an atom when it absorbs an electron is called electron affinity. It is also expressed in joules.
What is Electronegativity?
The measure of the tendency of an atom or molecule to attract electrons in a bond is called electronegativity.
What is metallic character.
Metallic character is the extent to which an element exhibits the physical and chemical properties of metals.
