Answer this asap pl Radio-1 FM has a frequency of 90 MHz.
a) What is this frequency in Hz?
The velocity of light is 3 × 108 m/s.
b) What is the wavelength of the waves arriving at your aerial?

Explanation:

a) 9 x 10 ^ 7 hz

b) v= (f) x ( lambda)

3 x10^8 / 9 x 10 ^7 = x

therefore x( lambda) = 3.33 m

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.

number of electrons for neutral cl