Answer:
2 Hertz
Explanation:
<em>The frequency would be 2 Hertz.</em>
<u>The frequency of a wave is defined as the rate at which the particles of a medium vibrates when the wave is passed through it while the period of a wave is the time it takes the particles to make a complete cycle of vibration.</u>
The frequency of a wave is inversely related to its period and is defined by the following equation:
f = 1/t, where f is the frequency (in hertz) and t is the period (in seconds).
Hence, if the period of a ripple is 1/2 or 0.5 seconds, the frequency becomes;
f = 1/0.5 = 2 Hertz
B - Atomic number. Dmitri Mendeleev organised the table according to atomic weight, however this caused problems with elements such as iodine and tellurium, Iodine has a higher mass, but a lower atomic number. And to make iodine in the same group as similar elements (halogens), Mendeleev had to break his own rules and put it before tellurium in the table. Moseley fixed this problem by ordering the elements according to atomic (proton) number.
<u>Question in English : </u>
<span>
<em>An atom X has 8 neutrons and its atomic number equals 8. Knowing that this atom is isotopes of Y, which has mass number 18, answer: What is the number of neutrons in atom Y?</em>
</span><span><u>Answer :</u>
</span>Isotopes are defined as the atoms which have same number of
protons but different number of neutrons of same element. Since the proton
number is same, the atomic number also same. Hence the atomic number of Y is 8.
Mass number = atomic number + neutron number
18 = 8 + neutron number
Neutron number = 10
Hence, there are 10 neutrons in Y.
