Question

18. Distinguish Isotopes from Isobar.
19. Differentiate mass number from atomic number
20. What is the characteristics of proton?
21. What is Cross pollination?
22. Write notes on phyllode
23. Write about the right way of protect the eyes?
24. How to keep your hair clean and health?
25. Define molecule​

Answer 1

Answer:

a

b

c

d

e

f

g

Explanation:

h

i

j

k

l

m

n

o

p

Answer 2

Answer:-

18) The difference between Isotopes from Isobar are:-

Isotopes

1. The atoms of the same element having same atomic number but different mass number.
2. For example:-

• Chlorine =

$\sf{ \large ^{35} _{17}Cl}$

Isobars

1. The atoms of different elements having different atomic number but the same mass number.
2. For example:-

• Argon and Calcium =

$\sf{ \large ^{40} _{18}Ar \: \: and \: \: \large ^{40} _{20}Ca}$

19) The difference between mass number from atomic number are:-

Mass number

1. The some of the neutrons and protons is termed as mass number.
2. It is generally represented by '' A ''.

Atomic number

1. The number of unit positively charged carried by the nucleus of an atom is termed as atomic number.
2. Atomic number is generally represented by '' Z ''

Example ↓

$\sf{ \large ^{ {}^{mass \: number} A} _{_{atomic \: number}Z}X} \longleftarrow \: symbol \: of \: an \: element$

Here,

A = Mass number

Z = Atomic number

X = Symbol of an element

20) The characteristics of proton are:-

1. A proton is A positively charged particle present in the nucleus of an atom
2. The charge of an atom is equal in magnitude and opposite in sign to that of an atom. Thus, a proton carries a unit of positive charge.
3. The mass of a proton is 1840 times that of an electron.
4. The symbol of proton is p+.

21. Cross pollination → The pollination that occurs between two flowers on two separate kinds of plant is called cross pollination.

Some advantages

• Ensures new varieties with new characters.
• disease-resistance new varieties are formed.

some disadvantages

• Flowers need to be centred and brightly coloured for cross pollination.
• It is a wasteful process as pollen grains are are to be produced in large number.

22) Phyllodes → These are green, flat coloured leaves. They, have modification like rachis or petioles.

23) The right ways to protect our eyes are:-

1. Splash water in eyes to keep them clean.
2. Avoid reading in dim light.
3. Do not look at the sun directly.
4. We should not play with sharp objects or put them inside eyes , ears, nose,etc.
5. Maintain proper distance while watching T.V. , computer or mobile phone.

24) We can keep our hair clean and healthy by :-

1. Washing hair regularly.
2. After bathing drying hair properly.
3. Applying , oil , comb and shampoo to keep them neat and clean.
4. Avoid using chemical shampoos.
5. Combing hair gently.

25) Molecules → All matter is made-up of a large number of extremely small particles called molecules. It is the smallest unit of matter which can exist independently and retain all it's physical and chemical properties.

↪ More Info ↩

• Matter is made up of atoms and molecules.
• An atom is smallest unit of an element which may or may not have an independent existence but it always takes part in a chemical reaction.
• There two types of pollination:-
• ▪ Self pollination
• ▪ Cross pollination.