Answer:
A. elements of the same kind with different numbers of neutrons
Explanation:
As we know that an atom is represented by
here we know that
z = atomic number
A = atomic number + number of neutrons
now if the number of neutrons in an atom is different but having same number atomic number then the combination of such group of atoms is known as isotopes.
So here we have
so above is the example of isotopes
The approximate speed of sound in dry (0% humidity) air, in meters per second, at temperatures near 0 °C, can be calculated from
Here
Temperature in Celsius
Replacing with our values we have that
Therefore the speed of sound in air at that temperature is 366.1m/s
Breaking down sugar (glucose) is a chemical change. Sugar is a compound that can be broken down.
Answer:
1.6 x 10⁻¹⁹ C
Explanation:
Let us arrange the charges in the ascending order and round them off as follows :-
1.53 x 10⁻¹⁹ C → 1.6x 10⁻¹⁹ C
3.26 x 10⁻¹⁹C → 3.2 x 10⁻¹⁹ C
4.66 x 10⁻¹⁹C → 4.8 x 10⁻¹⁹ C
5.09 x 10⁻¹⁹C → 4.8 x 10⁻¹⁹ C
6.39 x 10⁻¹⁹C → 6.4 x 10⁻¹⁹ C
The rounding off has been made to facilitate easy calculation to come to a conclusion and to accommodate error in measurement.
Here we observe that
2 nd charge is almost twice the first charge
3 rd and 4 th charges are almost 3 times the first charge
5 th charge is almost 4 times the first charge.
This result implies that 2 nd to 5 th charges are made by combination of the first charge ie if we take e as first charge , 2nd to 5 th charges can be written as 2e, 3e ,3e and 4e. Hence e is the minimum charge existing in nature and on electron this minimum charge of 1.6 x 10⁻¹⁹ C exists.
