4.1.2 The periodic table Flashcards
How are the elements in the periodic table arranged?
By increasing atomic (proton) number and so that elements with similar properties are in groups.
Q: Why is it called the periodic table?
Because similar properties occur at regular intervals.
Q: What do elements in the same group have in common?
A: They have the same number of electrons in their outer shell, giving them similar chemical properties.
Q: How does the position of an element in the periodic table relate to its electron arrangement?
A: The group number corresponds to the number of outer electrons, and the period indicates the number of shells.
Q: How can the periodic table predict reactivity?
A: By identifying the group and period, which relate to outer electron configurations.
Q: Why were early periodic tables incomplete?
A: Some elements were placed in inappropriate groups if strict atomic weight order was followed.
Q: How were elements initially classified?
A: By arranging them in order of atomic weights.
Q: How did Mendeleev address the limitations of early periodic tables?
A: He left gaps for undiscovered elements and reordered some elements based on properties.
Q: What confirmed Mendeleev’s predictions?
A: Discovery of elements that matched his predicted properties.
Q: How did the discovery of isotopes improve the periodic table?
A: It explained why atomic weight order sometimes disagreed with chemical properties.
Q: What type of ions do metals form?
A: Positive ions.
Q: Where are metals and non-metals located in the periodic table?
A: Metals are to the left and bottom; non-metals are to the right and top.
Q: How do the properties of metals and non-metals differ?
A: Metals are conductive, malleable, and form basic oxides, while non-metals are insulative, brittle, and form acidic oxides.
Q: How does atomic structure explain these properties?
A: Metals have delocalized electrons, while non-metals have more tightly held electrons in their outer shells.
Q: Why are noble gases unreactive?
A: Their atoms have stable electron arrangements (full outer shells).
Q: How does reactivity change down Group 7?
A: Reactivity decreases as the outer electrons are further from the nucleus.
Q: What is the general outer shell configuration of noble gases?
A: Eight electrons, except helium, which has two.
Q: How does boiling point change in Group 0?
A: It increases with increasing atomic mass down the group.
Q: What is the characteristic property of Group 1 elements?
A: They have one electron in their outer shell.
Q: What happens when Group 1 elements react with water?
A: They form alkaline hydroxides and release hydrogen gas.
Q: How can trends in Group 0 be used?
A: To predict properties of other elements in the group.
Q: How do Group 1 elements react with oxygen?
A: They form metal oxides (e.g., lithium oxide).
Q: How can trends in Group 1 be used?
A: To predict reactions of other alkali metals.
Q: What type of molecules do halogens form?
A: Diatomic molecules (pairs of atoms).
Q: How does reactivity change down Group 1?
A: Reactivity increases because the outer electron is further from the nucleus.
Q: What is the outer shell configuration of halogens?
A: Seven electrons.
Q: How do melting and boiling points change in Group 7?
A: They increase down the group.
Q: What happens in a halogen displacement reaction?
A: A more reactive halogen displaces a less reactive one from its salt solution.
Q: How can trends in Group 7 be used?
A: To predict the properties and reactivity of other halogens.
