Topic 1 - Key Concepts Of Chemistry - Periodic Table Flashcards
How did Mendeleev arrange the elements in his periodic table?
He ordered them by atomic mass, but not always strictly.
Mendeleev occasionally changed the order based on atomic weights and left gaps for undiscovered elements.
What was Mendeleev’s approach to predicting undiscovered elements?
He recognized that elements with similar properties belonged in the same groups.
This allowed him to leave gaps and place discovered elements where they fit best.
What did Mendeleev predict about the properties of undiscovered elements?
Some properties of elements were predicted and later confirmed with discoveries.
Elements with properties predicted by Mendeleev were later discovered and filled the gaps in his table.
Why was Mendeleev’s arrangement of elements based on increasing atomic mass not always accurate?
It was affected by the relative abundance of isotopes in some pairs of elements.
Knowledge of isotopes explained discrepancies in atomic weights.
What is the significance of atomic number in the periodic table?
It indicates the position of an element and the number of protons in its nucleus.
Elements are arranged by atomic (proton) number, and those in the same group have similar properties.
What do elements in the same group of the periodic table share?
They have the same number of electrons in their outer shell.
This characteristic gives them similar chemical properties.
Fill in the blank: Mendeleev left _______ for elements he thought had not yet been discovered.
gaps
True or False: Mendeleev’s periodic table was entirely based on strict ordering by atomic mass.
False
Mendeleev sometimes altered the order based on atomic weights.
What does the periodic table look like
The red line shows the divide between metals and nonmetals in the periodic table
How are elements arranged in the periodic table?
Elements are arranged in order of increasing atomic number, in rows called periods and elements with similar properties are placed in the same vertical columns called groups.
What are metals in the context of the periodic table?
Metals are elements that react to form positive ions.
Where are metals located in the periodic table?
Metals are found to the left and towards the bottom of the periodic table.
What is the majority type of element in the periodic table?
The majority of elements are metals.
How do metals achieve stability in their electronic structure?
Metals lose electron(s) to form positive ions, resulting in an electronic structure that is stable, like that of a noble gas.
What are non-metals in the context of the periodic table?
Non-metals are elements that do not form positive ions.
Where are non-metals located in the periodic table?
Non-metals are found towards the right and top of the periodic table.
How do non-metals achieve stability in their electronic structure?
Non-metals gain electron(s) to form negative ions, resulting in an electronic structure that is stable, like that of a noble gas.
Fill in the blank: Elements with similar properties are placed in the same vertical columns called _______.
groups
True or False: All elements in the periodic table can be classified as either metals or non-metals.
True
What does the electronic configuration of an element indicate?
It tells you how many electrons are in each shell around an electron’s nucleus.
The electronic configuration provides information about the distribution of electrons in an atom.
How is the electronic configuration of an element related to its position in the periodic table?
The electronic configuration indicates the number of electrons in the outermost shell and the period indicates the shell number.
Group 1 elements have 1 electron in their outer shell, while period 3 elements have their outermost electrons in shell 3.
What does the group number of an element indicate?
The group number indicates how many electrons are in its outermost shell.
For example, group 1 elements have 1 electron in their outer shell.
What does the period number of an element signify?
The period number signifies which shell the element’s outermost electron is found in.
For instance, period 3 elements have their outermost electrons in shell 3.
Fill in the blank: The first shell can hold a maximum of _______ electrons.
2 electrons
Fill in the blank: The second and third shells can hold a maximum of _______ electrons each.
8 electrons
