<span>Answer is: atomic number
of resulting atom is 88.
Alpha particle is nucleus of a helium-4 atom, which is made of
two protons and two neutrons.
Nuclear reaction: ²³</span>²Th → ²²⁸Ra + α (alpha
particle).
Alpha
decay is radioactive decay in which an atomic
nucleus emits an alpha particle (helium nucleus) and transforms
into an atom with an atomic number that is reduced by
two and mass number that is reduced by four.
Answer:
Because you can die if you dont be safe my guy.
If you dont
be safe in a lab it can be very dangerus and some times even deadly.
Tyler is gay
There are non-mercury thermometers with temperature and accuracy rangers equal to most mercury thermometers.
Answer:
1) Ca: [Ar]4s²
2) Pm: [Xe]6s²4f⁵
Explanation:
1) Ca:
Its atomic number is 20. So it has 20 protons and 20 electrons.
Since it is in the row (period) 4 the noble gas before it is Ar, and the electron configuration is that of Argon whose atomic number is 18.
So, you have two more electrons (20 - 18 = 2) to distribute.
Those two electrons go the the orbital 4s.
Finally, the electron configuration is [Ar] 4s².
2) Pm
The atomic number of Pm is 61, so it has 61 protons and 61 electrons.
Pm is in the row (period) 6. So, the noble gas before Pm is Xe.
The atomic number of Xe is 54.
Therefore, you have to distribute 61 - 54 = 7 electrons on the orbitals 6s and 4f.
The resultant distribution for Pm is: [Xe]6s² 4f⁵.
Answer:The earths plates shifting
Explanation: The movement releases stored-up 'elastic strain' energy in the form of seismic waves, which propagate through the Earth and cause the ground surface to shake.
