180 km/s V= 25
explanation: i had the same assignment
The atomic number(Z) is equal to the number of protons to equal to number of electrons.
The number of neutrons is equal to atomic mass minus the atomic number
n=A-Z
For Zn^2+, Z=28, e=28
For iron, Z=25,A=55
The number of neutrons is 55-25=30
The charge is zero
For O^2-, Z=8+2=10, n=p=10
The number of neutrons is 16-10=6
For sulfur, Z=16,A=34
For S2-, Z=16+2=18, A=34
The charge is 2-
- The atomic number is the basis of the periodic table.
- It is equal to the number of protons.
- The number of neutrons is atomic mass minus atomic number.
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B ............ is the answer,
Answer:
Bombardment by asteroids
Explanation:
All of the other ones explain themselves
