As per as the Multiplication rules of the significant figures, whenever any numbers in the decimals forms are multiplied or divided then result in mentioned in such a way so that the significant figures after the decimal will be same as that in the given least condition.
_______________________________
102900/12 = 8575
170 × 1.27 = 215.9
∴ (102,900 ÷ 12) + (170 × 1.27) = 8575 + 215.9
= 8790.9
Now, As per as Above rules, answer in correct significant figures will be = 8791.
<span>If two metals both have the same color, have similar densities, and are about the same size, but one is shiny and the other is dull, they can be separated based on the lustrous physical property of a metal. Lustrous is the property of the metal to shine/gleam gently because of its particle arrangement of atoms. </span>
Answer: 27 neutrons
Explanation:
Recall that the number of protons in the nucleus of an atom = Atomic number.
Hence, Calcium with mass number 47 and atomic number 20 will have 20 protons
Therefore, since Mass number = number of protons + neutrons
47 = 20 + neutrons
Neutrons = 47 - 20 = 27
Thus, there are 27 neutrons in radioactive calcium nucleus.
I believe it is A because the plant is offering protection while the bacteria is converting it in to nitrogen that the plant can use!