Which substance are highly soluble in water. 1. iron and glass 2. wood and salt 3. sugar and salt 4. wood and sugar?

The answer is option 3 that is Sugar and salt.

Sugar and salt are highly soluble in water while the other options that is of Iron , glass and Wood are insoluble in water.

Only sugar and salt are soluble in water.

For salt solubility there is different charge of sodium and chlorine that attract positive and negative area of water while for sugar , polar sucrose form intermolecular bond with water that makes it soluble.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.