Lesson 1.4

Question 1

Elements in the periodic table are arranged in rows and columns. The columns of elements
are called

Answer 1

groups,

Question 2

Elements in the periodic table are arranged in rows and columns. The columns of elements
are called groups, while the rows are called

Answer 2

periods.

Question 3

The periodic table also shows the division of elements to metals, metalloids, and nonmetals.
About three-quarters of the elements are metals that appear on the left-hand side of the
periodic table. The nonmetals appear on the right-hand side. Metals and nonmetals are
separated by a group of elements that form a staircase-like line in the periodic table.

Question 4

Metals are lustrous or shiny as light is reflected on its
surface. Metals are also ductile as they can easily be
drawn into wires and are malleable or can be easily
hammered into thin sheets. These elements are also
good conductors, which means that heat and electricity
can pass through them easily. Since most metals are
able to conduct heat and electricity, they also have a
high melting point, which enables them to withstand
heat without turning into liquid immediately. Metals
have a high boiling point, which prevents them from
easily evaporating when heated.

Question 5

Nonmetals, except for bromine, are either solid or gas
at room temperature. Solid nonmetals are usually
brittle or easily break when subjected to a strong force.
Though there are some nonmetals that are hard, some
exist in powdered form due to their softness. Unlike
metals, nonmetals are usually dull in appearance and
exhibit no luster. Also, nonmetals are poor conductors of heat and electricity but have
relatively low melting and boiling points.

Question 6

Some elements exhibit properties of both metals and nonmetals. These elements are
known as metalloids or semimetals. Their most distinct property is their ability to conduct
electricity but not as good as metals. This is the reason why metalloids are known as
semiconductors. A semiconductor is a material that can conduct some electricity better
than an insulator, but now as much or as well as how metals conduct electricity.