Question

Sodium, Aluminum, Beryllium, Calcium, Iron etc. are all metallic elements. Which of the following are their characteristics?
A. Good conductors of heat and electricity
B. Electropositive in nature
C. Malleable, that is, can be beaten into thin sheets.
D. Solid at room temperature.

Answer 1

Hint: All the elements can be divided into three categories. They are: metals, nonmetals and metalloids.
Metals: An element that can readily form positive ions and can donate electrons and form metallic bonds is called a metal. All metals have few properties – metallic luster, conducting capacity of heat and electricity, malleability and ductility and so on.
Nonmetals: An element that can readily form negative ions and can accept electrons is called a non-metal. Non-metals have the opposite properties of that of the metals.
Metalloids: An element which has intermediate properties of that of metals and non-metals is called a metalloid. They are usually used as catalysts, semiconductors etc.
Using these definitions, we can answer the question.

Complete answer:
Let’s read every option.
Option A: Good conductors of heat and electricity
We know that all metals are very good conductors of electricity. They have free electrons in their valence shell and losing them will give the nearest noble gas configuration, hence a good conductor. They have melting points and hence will not melt very easily during transfer of heat.This option is correct.

Option B: Electropositive in nature
The tendency of an element to donate electrons and to readily form positive ions is called electro-positive character. Metals have either 1,2 or 3 electrons in their valence shell and hence after donating them, they gain the nearest noble gas configuration. They are highly electro-positive in nature.
This option is also correct.

Option C: Malleable, that is can be beaten into thin sheets.
All the metals possess the malleability and ductility properties.Malleability means that it can be pressed or shaped into thin sheets without cracking. Ductility means that it can be drawn out to be a thin wire without losing its toughness.Therefore, this option is also correct.

Option D:Solid at room temperature.
All metals are solid at room temperature and all non-metals are gaseous or solid at room temperature. There are valence electrons in atoms that can easily be shared, hence these metal elements have a very strong metallic bonding between them. Hence this option is also correct.

Therefore, all the four options are correct.

Note:We need to have a grip on definitions of metals, nonmetals and metalloids and their properties in order to solve this question. However, there are a few exceptions like:
-Mercury is the only metal which is liquid at room temperature (used in thermometers), bromine is the liquid non-metal.
-Not all metals are very strong. For example: sodium, lithium, potassium are very soft and can be cut with a knife.
-Bismuth is a poor conductor of heat which is a metal whereas graphite which is a non-metal is an excellent conductor of electricity.
Since these are only a few exceptions, the properties can be generalized for all metals, nonmetals and metalloids.