Atomic Structure And Periodic Table Flashcards
(22 cards)
What are atoms?
Atoms are the building blocks of matter.
What are the three sub-atomic particles that make up an atom?
Protons, neutrons, and electrons.
What charge do protons have?
Protons have a positive charge.
What charge do neutrons have?
Neutrons have no charge (neutral).
What charge do electrons have?
Electrons have a negative charge.
What do protons, neutrons, and electrons together make?
They make all the atoms in the universe.
What is the Solid Sphere Model?
Dalton’s model stating that atoms are indivisible and identical for a given element.
Atoms of different elements combine to form compounds.
Who proposed the Plum Pudding Model?
J.J. Thomson in 1904, depicting atoms as electrons scattered in a positive charge cloud.
Thomson discovered electrons in 1897.
What did Rutherford’s gold foil experiment demonstrate?
That atoms are mostly empty space with a concentrated positive charge in the nucleus.
This led to the realization that positive charge is localized in the nucleus.
What was Bohr’s contribution to atomic theory?
He proposed that electrons move in fixed orbits around the nucleus with quantized energy levels.
This explained the emission spectra of some elements.
What year did John Dalton propose his atomic theory?
1803.
What year did J.J. Thomson propose the Plum Pudding Model?
1904.
What year did Ernest Rutherford conduct his gold foil experiment?
1911.
What year did Niels Bohr propose his model of the atom?
1913.
What is the number of protons in the nucleus of an atom called?
Proton number
The proton number determines the identity of the element.
What does the periodic table arrange elements by?
Increasing atomic number
The atomic number is the number of protons in the nucleus.
What are the columns of the periodic table called?
Groups
Groups indicate the number of electrons in the outer shell.
What do the rows of the periodic table represent?
Periods
The top row is the first period.
True or False: The periodic table is organized by decreasing atomic number.
False
The periodic table is organized by increasing atomic number.
What does the group number indicate about an element?
Number of electrons in the outer shell
This is crucial for determining chemical reactivity.
Fill in the blank: Elements in the same group typically have similar _____ properties.
Chemical
This is due to having the same number of valence electrons.
True or False: All elements in a period have the same number of electrons in their outer shell.
False
Elements in a period have varying numbers of electrons in their outer shell.
