The answer is D. Gold. Malleability, the ability for a material to be hammered or shaped into thin sheets, is a common property of metals. Among the choices, gold is the only metal. Also, gold is considered to be the most malleable metal.
The cell notation is:

here in cell notation the left side represent the anodic half cell where right side represents the cathodic half cell
in anodic half cell : oxidation takes place [loss of electrons]
in cathodic half cell: reduction takes place [gain of electrons]
1) this is a galvanic cell
2) the standard potential of cell will be obtained by subtracting the standard reduction potential of anode from cathode


Therefore

3) as the value of emf is positive the reaction will be spontaneous as the free energy change of reaction will be negative
Δ
As reaction is spontaneous and there will be conversion of chemical energy to electrical energy it is a galvanic cell.
Answer: since the sodium ion is Na+, and sulfate is SO4(2-), you'll need 2 sodiums for a sulfate, making sodium sulfate Na2SO4.
Explanation:
I don't know if this will help but here are some chemical properties of acids and bases :
taste: sour (vinegar)
base: bitter (baking soda)
smell: frequently burns nose
base: usually no smell (except NH3)
texture: sticky
base: slippery
reactivity: frequently react with metals to form H2
base: react with many oils and fats
There are multiple factors that contribute to the cost of a mineral.
First of all is the demand or application, which will be related to its
physical properties. For example, nontarnishing metals like gold are
held in high value for their appearance. Second is the supply of the
mineral, those that only have a small quantity in the earth's crust are
likely to be more expensive. Third is the cost of extraction and
manufacturing. Some minerals may be abundantly found, but may be
distributed over a wide area, meaning that it is still expensive to mine
and transport.