CLASS 9 SCIENCE METALS AND NON-METALS NOTES

METALS AND NON-METALS

1. Tick (✅) the correct alternative:

a. Which is a liquid metal?
= i. mercury

b. Which one of the following is a metal?
= i. Na

c. Which one of the following materials shows the property of malleability?
= i. Silver

d. What is the property of a metal by which it can be drawn into wires?
= i. Ductility

e. What is said to be the shining properity of metals?
= i. lustrous

f. Which metal is found in human blood?
= i. Fe

2. Short answer type questions:

a. Give an example of a shining non- metal and an example of the best conductor of heat.

→Metals are shiny malleable, ductile generally heavy and good conductors of heat and electric, example shining non-metal is iodine.

b. What is a malleable metal?
→Metals which have the property of beaten inta sheets is called malleable metal.

c. What is metallic bond?
= The chemical banding that holds the atoms of a metal freely together is called metallic bond.

d. Which non-metal can conduct electricity?
→ Graphite non-metal can conduct electricity.

e. What is metallic lustre ?
→ The shining property of metals is called metallic lustre.

f. Name any two soft metals.
= Sodium, Potassium

g. What are the metals found as minerals in human body?

= Metals like Zinc (Zn), Sadium (Na), Potassium (K), Iron (Fe), etc are the metals found as minerals in human body.

h. Write four plant sources of iron in human body.
= White beans, kidney beans, peas, nuts are four plant source of iron in human body.

i. Name two metals which are havorful to human beings.

= i. Mercury (Hg)
ii. Lead (Pb).

j. What is the difference between conductor and insulator?

= * Conductor
i. Those substances through which electricity can flow are conductors.
ii. Generally metals are conductors Ex: silver, copper, etc.

* Insulator
i. Those substances through which electricity cannot flow are insulator.
ii. Generally non-metals inculador Ex: wood, rubber, etc.

3. Long answer type questions.

a. Enlist any five properties of metals and non-metals each.

= The five property of metals are:

i. Malleability

ii. Sonorous Sound

iii. Duedility

iv. Conductivity

v. Metallic lustre

* The five property of non-metals are:

i. They are not sonority.

ii. They are bad conductor of heat and electricity.

iii. They are not malleable and ductile.

iv. Their melting and boiling points are both low. 

v. Non-metals are found in many colour.

b. Give an example of mental which:

i. is a liquid at room temperature.

→ Mercury

ii. is a poor conductor of electricity

= Lead

iii. it can be easily cut with a knife.

= Sodium 

c. What would you observe when Zine is added to a dilute hydrochloric acid? Write the chemical reaction that takes place.

= When zine is added to a dilute hydrochloric acid, a bubbling reaction will occur as hydrogen gas is produced. The chemical reaction is as Follows:

Zn+ dil 2HCI

d. Write the reaction equation for:

i. calcium and water 

= Ca+2H₂O → Ca(OH)2 + H₂ (Hydrogen)

ii. Sodium and oxygen

= 2 Na + O₂ = Na₂O₂

iii. magnesium and hydrochloric acid. 

= 2 HCl → MgCl₂ + H₂ → Mg + 2HC1-

e. An element reacts with compound with a high melting paint. This compound is also soluble in water, bWhich element-Cali or carbon is it likely to be?

= It is likely to be calcium, as calcium compound typically have high melting paints and are soluble in water Carbon compounds, on the other hand, usually have low melting prints and are not very capable in water.

f. Graphite and lodine are non-metals but they shine Explain it with suitable reasons.

→Graphite and iodine and iodine are non-metals because they do not have the properties of metals However, they do shine because they. are highly reflective Graphite reflects about 97% of light that hits its surface, and iodine reflects about 86%. This is because non-metal state have a higher refractive index than metals.

g. Compare between metals and non-metals on the basis of their chemical properties.

= The chemical properties of metals are:
i. Generally metals react with oxygen to form basic metallic oxides.

ii. Metals react with dilute acids to form metallic salts and hydrogen gas.

iii. Most of the metals do not react with water. However, metals like sodium, potassium and calcium react vigorously with water to produce metallic hydrazide and hydrogen gas.

→ The chemical properties of non-metals are: 

i. Non-metals react with oxygen metal oxide. Ex: C+O2= CO₂

ii Non-metals do not react with water and acids to evolve hydrogen gas.

iii. Non-metals such as sulphur and hydrogen read and form hydrogen sulphide. Ex: S+H2=H2S

h. Write any three points to show the importance of each.

= a. Zinc (Fe)

i. It helps to increase the immune system of the body.

ii. It prevents cell damage in the retina and vision.

iii. It helps in the call division and growth development of bones.

b. sodium (Na)
i. it helps to transmit impulses for nerve function.

ii. It regulates the contraction and relaxation of muscles

iii. it regulates the acid-base balance of body and body fluids.

c. Potassium (K)

i. it regulates muscle contraction.

ii. It maintains the electrolyte balance in the body.

iii. It increases the heart function and working ability of the nervous system.

i. Mercury and Lead are harmful metals for human beings. How are these metals harmful? Suggest your views.

→ Mercury is harmful metals for human beings by given reasons:

i. It causes high blood pressure, alters heard beat  rate and increase the risk of heart attack.

ii. It causes loss of pheripheral vision, lack of coordination in movements and muscle weakness.

iii. Mercury compounds badly affect the growth of the brain and the Nervous system in children.

* Lead is harmful metals for human being by given reasons:

i. Sometimes, ingestion of lead can cause seizures, Coma and even death.

ii. It decrease the transportation of calcium and oxygen.

iii. It causes teeth decay, headache, stomachache kidney disorder, increased blood pressure and incidence of hypertension.

j. You are given two samples, how do you differentiate which one is metal and which is non-metal ?

= I differentiate which one is metal by given properties Malleability, Ductility, Conductivity, Sonorous sound, Metallic lustre, Hardness, High melting point and samples which doesn't have these properties are non-metal.