The third one beacuse if you count all the atoms of every one you will find that one the left side, you have 3 h and on the right you have 2 h
Speed=distance/time
D=150km
S=7200s
Divide the numbers.
150/7200=0.02km/s <---final answer
B- is the answer
Hope this helps
Have a nice day~
Answer:
The correct answer is because they have same number of protons but different number of neutrons.
Explanation:
Isotopes are atoms of the same element but differ only in the number of neutrons in the nucleus, i.e. they have same atomic number but different mass number.
Mass number is affected as they have different number of neutrons, thus effecting their physical properties.
The number of electrons and protons are same, i.e. their atomic number is same and thus their chemical properties are same as chemical properties are determined by the atom’s electronic configuration and that relates to number of protons.
