Answer:
Explanation:
Atom X,
Neutron num = 4, Mass num = 7
Therefore, proton number = Mass num - Neutron num
= 7 - 4
= 3
Atom Y,
Neutron num = 5, Mass num = 9
Therefore, proton number = Mass num - Neutron num
= 9 - 5
= 4
1) False. Atom X belongs to group 3 while atom Y belongs to group 4
2) False. Atom X is in a column on the left of Atom Y
3) True. Atom X and atom Y belong to the same period two on the periodic table
4) Fasle. Atom X and Y are not isotopes because they do not have the same atomic number.
Isotopy is a phenomenon whereby atom of same element have same atomic number but different mass number
Moles of glucose = Molarity x volume solution
= 4.5 x 1.5
= 6.75 moles.
Hope this helps, have a great day ahead!

The Balanced equation will be :

The Coefficients are :
_____________________________

<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.