#24 why did mendeleev leave spaces in his periodic table?

#24 Why did Mendeleev leave spaces inhis periodic table?

He could tell from the elements surroundingthe “holes” in his table that they must exist.

#25 What effect did the discovery of gallium haveon the acceptance of Mendeleev’s table?

His ability to predictthe properties and existenceof unknown elements madehis table much more believable

#26 What pattern is revealed whenthe elements are arranged in a periodic table in order of increasingatomic number?

Many trends are revealed such aselectronegativity, atomic and ionic radii,

#27 Based on their locations in theperiodic table, would you expectcarbon and silicon to have similarproperties?

Yes, theyare in the same group

#28 Identify each property below asmore characteristic of a metal or anon-metal.a. gas at room temp.

non-metal, think of oxygen gas

#28 Identify each property below asmore characteristic of a metal or anon-metal.b. brittle

non-metal, think of a piece of lead in your pencil--Carbon

#28 Identify each property below asmore characteristic of a metal or anon-metal.c. malleable.

metal: think ofpounding a pieceof gold into leaf with amallet.

#28 Identify each property below asmore characteristic of a metal or anon-metal.d. poor conductor of electric current.

non-metal: think of how wellmetal conducts electricity. ie.a wire.

#28 Identify each property below asmore characteristic of a metal or anon-metal.e. shiny.

metal: think of a shinypiece of silver or gold.

#29 In general, how are metalloidsdifferent from metals and nonmetals?

Metalloids have properties that aresimilar to both metals and non-metals. How a metalloid behaves depends on the conditions.

#30 Where are the alkali metals, the alkaline earth metals, the halogens, and the noble gases?

#31 Which of the following aresymbols for representative elements:NaMgFeNiCl

#32 Which noble gas does nothave eight electrons in its highest occupied energy level?

Helium;it only has twoall othershave 8 valenceelectrons

#33 Which of these metals isn’t a transition metal?a. aluminumb. silverc. irond. zirconium

Transition metals are light blue in thistable

#34 Use figure 6.12 to write theelectron configuration of these elements.a. B b. As c. F d. Zn e. Al

#35 Write the electron configurationsof these elements:

a. the noble gas inperiod 3

b. the metalloid in period 3

c. the alkali metal in period 3

Ar: 1s22s22p63s23p6

Si: 1s22s22p63s23p2

Na: 1s22s22p63s1

#36 Which element in each pairhas atoms with a larger atomic radius?a. sodium, lithium

#36 Which element in each pairhas atoms with a larger atomic radius?b. strontiummagnesium

#36 Which element in each pairhas atoms with a larger atomic radius?c. carbongermanium

#36 Which element in each pairhas atoms with a larger atomic radius?d. seleniumoxygen

#37Explain the difference between the first and second ionization energy of an element.

First ionization energyis the energy required to removethe FIRST electron

Second ionization energy is the energy required to remove theSECOND electron. It is always GREATERTHAN the first ion-ization energy

#38 Which element in each pair hasa greater first ionization energy?a. lithium boron

Boron

#38 Which element in each pair hasa greater first ionization energy?a. magnesiumstrontium

Magnesium

#38 Which element in each pair hasa greater first ionization energy?a. cesium aluminum

Aluminum

#39 Arrange the following groupsof elements in order of increasingionization energy.

SrMgBe

#39 Arrange the following groupsof elements in order of increasingionization energy.

CsBaBi

#39 Arrange the following groupsof elements in order of increasingionization energy.

NaAlS

Atomic Radius as comparedto IONIC radius

Ions

Atoms in elemental form (same #of electrons as protons)

1

1

1

1

1