Atomic Structure Flashcards
What are the 3 sub-atomic particles in an atom?
Protons, Neutrons and Electrons
Where are Protons located within an atom?
In the nucleus
Where are Neutrons located within an atom?
In the nucleus
Where are Electrons located within an atom?
In electron shells/orbitals around the nucleus
What is the charge of a proton?
Positive
What is the charge of a neutron?
Neutral
What is the charge of an electron?
Negative
Do scientists today know what an atom looks like? Why or why not?
They are the building blocks of all matter. They are too small to see with the naked eye or even a microscope. So scientist do not know exactly what an atom looks like,
What is the mass of a proton?
1 AMU (atomic mass units)
Which sup-atomic particles contribute to an atoms mass or atomic mass?
The sum of the protons and neutrons in an atom equals the atomic mass.
What is the role of a proton?
Form the identity of an atom. (e.g. a substance with 1 proton is Hydrogen. A substance with 6 protons is carbon)
What is the mass of a neutron?
1 AMU (atomic mass units)
Which sub-atomic particles make up the nucleus of an atom?
Protons and neutrons make up the nucleus of an atom.
What is the mass of an electron?
Electrons weigh nothing (0 AMU), they are much smaller than protons and neutrons.
What is the atomic number?
The atomic number is the number of protons in an atom. The number of protons in an atom is equal to the number of electrons.
Why is the model of an atom constantly changing over time?
The model of an atom or the atomic model is constantly changing because, over time, scientists’ understanding of an atom grows and so does the way they view an atom.
What did the Ancient Greeks understand about an atom?
Matter is made up of particles, but not the elements as we know them today.
What did Robert Boyle (1600s) identify about an atom?
Robert Boyle identified gold and silver as being elemental.
What did Dalton (1700s) theorize about atoms?
That the basic unit of matter is a tiny particle called an atom. And all elements are composed of indivisible atoms. The atoms of one element are identical to each other but different to those of another element.
After Dalton’s theory about atoms, what did experiments prove wrong about his theory?
Atoms ARE indivisible.
What did J.J. Thomson and his ‘Plum Pudding Model’ discover about atoms?
Electrons are relatively low in mass and possess a negative charge. Because atoms are electrically neutral, some part of the atom must possess a positive charge equal to that of electrons to balance the electrical charge.
What did Rutherford conclude about atoms?
The atom is 99.99% empty space. And that the nucleus, which is approximately 100, 000 times smaller than the rest of the atom, contains a positive charge and the mass of the atom.
What is the valence shell or valence electrons?
Electrons in the outermost shell of an atom.
