Answer: 63.6 u
Explanation:
RAM = RAM of isotope-1 X (% abundance) + RAM of isotope-2 X (% abundance) ÷ 100
63 X 70% + 65 X 30% ÷ 100 = 63.6 u
<span>Magnetic declination is the angle between magnetic north (the direction the north end of a compass needle points) and true north. The declination is positive when the magnetic north is east of true north. The term magnetic variation is a synonym, and is more often used in navigation. Isogonic lines are where the declination has the same value</span>
Chemical reactions are ultimately the reconfiguration of reactants to form products that are in a more energetically favourable state. In this sense, the vast majority of chemical reactions have reactants and products that are at different energy levels.
This means that energy either has to enter or leave the chemical compounds. Some of this energy is in the form of heat, which will cause the system to cool down or heat up.
So, detecting a change in temperature is a good way to find out if a chemical reaction has occurred. Of course, chemical reactions can occur with no detectable change in temperature, and a change in temperature does not necessarily confirm a chemical reaction has occurred.
Answer:
Mass = 114.26 g
Explanation:
Given data:
Number of gold atoms = 3.47×10²³ atoms
Mass in gram = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
3.47×10²³ atoms × 1 mol /6.022 × 10²³ atoms
0.58 mol
Mass of gold:
Mass = number of moles × molar mass
Mass = 0.58 mol × 197 g/mol
Mass = 114.26 g
We subtract the enthalpies of the reactants from that of the products:
Since this is < 0, this is an exothermic reaction.