U-238
The number besides the U means its total molar mass. The molar mass of this element is 238
Molar mass= protons + neutrons
This means that 238= 146 + protons
Do 238 - 146
Answer is 92
From,
RAM=element×its relative abudance/total abudance
=((107×13)+(12×109))/25
The answer is=107.96
Answer:
bromine (Br)
Explanation: Iron enters into a reaction with substances of different classes, and interacts with oxygen, carbon, phosphorus, halogens (bromine, iodine, fluorine and chlorine), and also nitrogen. These are not all the reactions of iron – this metal reacts with many elements.
The melting of solid wax to form liquid wax and the evaporation of liquid wax to form wax vapor are physical changes. The burning of the wax vapor is a chemical change.
