Class 10 Science Chapter 3 Metals and Non Metals

As you have learned in class 9 that normally elements are divided into metals, non-metals, and metalloids. So, in class 10 science chapter 3 metals and non metals, we are going to discuss metals and non-metals only.

All the metals are natural compounds that are present in the earth’s crust. They are mainly found in the form of metal ores which are associated with many other elements. All metals are good conductors of electricity. Also, they are opaque, lustrous elements.

Usually, all the metals are solid in nature except a few such as mercury is liquid at room temperature. However, if the metal is pure its surface becomes shiny.

Class 10 Science Chapter 3 Metals and Non Metals

Here we are going to discuss that what are physical properties of metals and non-metals. But, before that, let’s first understand what are non-metals?

Non-Metals: These are bad conductors of electricity. Most of the non-metals are gases such as hydrogen, oxygen, etc. but there are some which are solids except for bromine which is liquid in nature.

# Physical Properties of Metals and Non-Metals

In this section of Class 10 science chapter 3 metals and non Metals, we will discuss in detail the physical properties of metals and non-metals.

First, let’s talk about the Metals:

  • Metals are good conductors of electricity. This is because they have free-moving electrons in them.
  • These are physically lustrous, which makes them shine such as Gold is used to make jewelry. This property is also known as metallic luster.
  • They have high melting and boiling points.
  • Metals don’t have any flexibility and have tensile strength.
  • These are good conductors of heat also.
  • These are used to make thin wires, that is why we can say that they are ductile in nature.
  • Metals are solid at room temperature except for mercury which is liquid.

Now, let’s talk about the non-metals:

  • Non-metals are also known as insulators that’s why they are poor conductors of electricity.
  • They don’t have a lustrous property like metal which makes them dull to look.
  • They have low density and hence they are weak as compared to metal.
  • These can be solid, liquid, or gas in nature.
  • They have low melting and boiling points, which makes them a bad conductor of heat.

Class 10 Science Chapter 3 Metals and Non Metals

Now that we are familiar with the chemical properties, let’s move on to the chemical properties of metals and non-metals. In this section of class 10 science chapter 3 metals and non metals, we will specifically learn about the chemical nature of both these elements.

# Chemical Properties of Metals and Non-Metals

First, let’s learn about metals:

  • Most of the metals react with oxygen to make metal oxide. such as when we heat copper in the air it produces 2 copper oxides. See equation below:

Equation: 2Cu\ +\ O_2\rightarrow2CuO

  • As we read in Chapter 2, metal oxides are basic in nature. But some metal oxides show both basic and acidic behavior such as aluminum oxide and zinc oxide.

Equation: Al_2O_3\ +\ 2NaOH\ \rightarrow\ 2NaAlO_2\ +\ H_2O

  • Most metals are insoluble in water, except sodium and potassium oxide. Which reacts with water to produce alkalies.

Equation: Na_2+\ H_2O\ \rightarrow\ 2NaOH

  • Metal like sodium and potassium when reacting with water causes the exothermic reaction to happen. Which produces hydrogen and catches fire. However, metals like lead, copper, silver, and gold don’t react with water at all.
  • Metals when reacts with acid they produce salt and hydrogen gas.

Now, let’s learn about non-metals:

  • Most of the non-metals don’t produce anything when they react with air at room temperature. Except for the white phosphorus.
  • Usually a non-metal only react with other non-metal at room temperature.
  • Usually, non-metals do not react with water except for chlorine, as it dissolves in water and forms an acidic solution. We mainly use chlorine to clean the water.

# Reactivity series of metals

In this section of class 10 science chapter 3 metals and non metals, the series is arranged in decreasing order of the reactivity of metals. See the table below:

class 10 science chapter 3 metals and non metals reactivity series of metals
Element Name Element symbol
Potassium K
Sodium Na
Calcium Ca
Magnesium Mg
Aluminum Al
Zinc Zn
Iron Fe
Lead Pb
Hydrogen H
Copper Cu
Mercury Hg
Silver Ag
Gold Au

As you can see in the table, Potassium is the most reactive, and Gold is the least reactive after the displacement reactions.

Class 10 Science Chapter 3 Metals and Non Metals

In this section of class 10 science chapter 3 metals and non metals, we will learn about how metals and non-metals react. Both metal and non-metal have this tendency to make their valance shell filled. However, all the noble gas have their valance shell properly balanced and filled.

Metals are electropositive in nature they have the tendency to lose the electrons of their outer shell to attain the noble gas configuration. Such as Sodium, which has 1 electron in its outermost shell and needs to lose 1 electron to stable its shell.

Also, non-metals are electronegative in nature they have the tendency to gain electrons to attain the noble gas configuration. Such as Chlorine, which has 7 electrons in its outermost shell and needs to gain 1 electron to stable its shell.

Equation: \dot{Na}\ +\ \begin{matrix}\ &x&x\\x&Cl&x\\x&x&x\\\end{matrix}\ \rightarrow\ \left({\rm Na}^+\right)\left[\begin{matrix}.&x&x^-\\x&Cl&x\\x&x&x\\\end{matrix}\right]

Here:

  • Na → Sodium
  • Cl → Chlorine
  • x → Electrons
  • + and – → ion charge of the element

In this reaction, sodium needs to lose 1 electron whereas chlorine needs to gain 7. So, when they both react with each other they produce Salt (NaCl). This product is also known as an iconic compound.

# Properties of Ionic Compounds

In class 10 science chapter 3 metals and non metals, we will be introduced to the properties of ionic compounds. Following are the main points that you must remember.

  • All of these compounds are solid because of the strong bond between them, i.e. positive and negative charge.
  • These compounds have high boiling and melting points.
  • Those compounds that are ionic but still have a valance electron in their outer shell are soluble in water such as petrol, kerosene, etc.
  • These compounds conduct electricity when they are dissolved in the water.

Here is the table containing the information about the boiling and melting point of some ionic compounds.

Melting and boiling points of ionic compounds in class 10 science chapter 3 metals and non metals
Ionic Compound Melting Point (K) Boiling Point (K)
NaCl 1074 1686
LiCl 887 1600
CaCl2 1045 1900
CaO 2850 3120
MgCl2 981 1685

Class 10 Science Chapter 3 Metals and Non Metals

Metals are mainly found in the earth’s crust. However, some of the metals are also in seawater such as sodium chloride, magnesium chloride, etc. Metals are found in 3 states, see the reactivity table above, so, those elements who are lowest in the table are found in the free states in nature such as gold, silver, and copper, etc.

Those metals which are found top in the table are found in the reactive state in nature such as Potassium, Calcium, etc. So, the middle element in the table is found in the moderate reactive state in nature such as Zinc, Iron, etc. Although, ores of many metals are found in oxide in nature.

In class 10 science chapter 3 metals and non metals, we will see how metals can be extracted from their ores using different techniques.

# Extracting Metals

Most metals occur in the combined state in nature but sometimes they also occur in the free state. However, there are 3 types of metals that occur in nature.

1. Metals that are low in reactivity series

These metals are very unreactive in nature so, you can get them by heating them. For example when you heat ore of mercury i.e. cinnabar, then you get mercuric oxide. When you heat this more you can get mercury out of it.

2. Metals that are middle in reactivity series

These metals are moderately reactive in nature so, you can get them by using any of 2 techniques i.e. roasting or calcination. Such as sulfide ores are converted into oxides by roasting. Also, carbonate ores are changed into oxides by calcination.

What is Roasting?

Roasting: When we heat an ore lower than its melting point in the presence of oxygen/air then it is known as roasting.

What is Calcination?

Calcination: When we supply the air in a limited amount or we just heat the ore in the absence of air, then it is known as calcination.

3. Metals that are top in reactivity series

These metals are very reactive in nature so, we can’t get these metals by heating them. So, these are obtained by electrolytic reduction.

What is Electrolytic reduction?

Reduction is a process that involves the gain and loss of electrons by a chemical type. So, the electrolytic reduction is a type of electrolysis in which we pass the electric current through the ionic substance by this a chemical reaction produced at the electrodes.

Class 10 Science Chapter 3 Metals and Non Metals

In this section of class 10 science chapter 3 metals and non metals, we are going to learn about refining metals and corrosion.

# Refining

Refining means purifying the impure metals. In other words, this is a process from which we separate the metals from the impurities which are surrounding them. Such as gold being surrounded by the rocks around it.

There are many methods you can use for refining metals such as:

  • Distillation: Metals will be vapourised first and then condense back to get them such as mercury.
  • Electrolysis: Metals will be collected by passing an electric current in a liquid solution such as copper.
  • Liquation: Metals will be melted using heat and collected in liquid forms, such as lead.
  • Chromatographic: Metals crude put into the liquid or gaseous medium. Then this medium is moved through an adsorbent to obtain the metal in pure form.
  • Zone refining: Metals will be obtained from melted form, so melted metal travels through the material to be refined, such as silicon.
  • Vapor phase refining: Metal will be obtained from converting it into the volatile compound and after that again decomposing it such as nickel.

#Corrosion

We already talked about corrosion in science chapter 1 chemical reaction and equation. So, we already know that:

  • Silver turns into black in color after the corrosion.
  • Copper turns into green.
  • Iron turns into brown flaky also known as rust.

Let’s talk about how we can prevent corrosion and save our surroundings from this. So, if you want that your iron items don’t corrode or catch rust, then you have to paint or oil or grease them. But the best thing to do to metal is to make their alloys, like when we mix iron with nickel and chromium, we get stainless steel.

Also, the melting point of the alloy is less than the pure metal, so, they can survive in the environment more than just metal.

Class 10 science chapter 3 metals and non metals blueprint
1 Marker 1 question
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Total questions 3
Total marks 6
Class 10 Science Chapter 3 Metals and Non-Metals Blueprint 2021-22

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Updated: January 1, 2022 — 5:57 am

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