Answer: option A.
A physical change occurred in which the iron remained iron, but lost one of its physical properties
Explanation: magnetization and demagnetization is a physical change as no new substance is form and it is easily reversed. When an iron rod is magnetized, it can loss it magnetic property by hitting it. So when an iron rod which is magnetized falls from a height it can also loss its magnetic property
the correct answer is A.
Each atom has three sub particles, which are electron, proton and neutron. To get the atomic mass for each atom, one has to add the masses of the proton, neutron and electron in an atom. For each atom, the major contributors to its mass are proton and neutron, this is because the mass of the electron is very small indeed. Thus, the atomic mass of an element is usually in the range of its mass number, which is obtained by the summation of proton and neutron. Since it is the number of proton that indicate an atomic number and it is the mass number that indicate atomic mass, therefore, atomic mass can be greater than the atomic number.
The precipitate that is most likely formed from a solution containing Ba+2, Li+, OH-1, and CO3^-2 is BaCO3.
This is because carbonates of all metals except sodium, Lithium potassium (group 1) and ammonium are insoluble in water. Hydroxides of sodium, Lithium, potassium and ammonium are very soluble in water, calcium and barium are moderately soluble. Ba(CO3) is insoluble in water and therefore forms a precipitate.