Question

15. Which of the following statements are incorrect?
i) Phosphate ion is a trivalent and positive ion
ii) Calcium ion is trivalent and positive
111) Phosphorus is a polyatomic molecule
iv) Aluminium ion is divalent and positive
1) i and in
2) iii and iv only
3) i, ii and iv only
4) i, ii and iii only​

Answer 1

Answer:

Case B : Sound wave in air is the longitudinal wave. so B is not true

Case C because of higher temperature means molecules having higher energy and moving faster than in cold temperature

case D :

L=10log

I

o

I

30

60

=

10log

I

o

I

2

10log

I

o

I

1

2log

I

o

I

2

=log

I

o

I

1

so I

2

=2I

1

is not true.