The density of the block will be "7.11 gm/cm³". A further explanation is provided below.
Given values are:
Density of iron,
Mass of block of metal,
Volume of block,
By using the formula,
→ 
then,
→ The density of block will be:
= 
= 
= 
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You can tell the difference by How shiny it is and by how heavy it is
D & e represent the same element
Answer:
(d) Why is the fuel cell in Question (c) described as an alkaline fuel cell? (e) Another type of fuel cell uses methanol instead of hydrogen.
Explanation:
Answer:
Passivation of Oxide layers of the metals.
Explanation:
Passivation is a non-electrolytic finishing process that makes most metals rust-resistant. The prosses removes free iron from the surface by using either nitric or citric acid. When this happens, it results to an inert, protective oxide layer that is very slow or less likely to chemically react with air and cause corrosion.
Passivity caused many of the metals several minutes to begin to react. Once the finishing process that makes metals less likely to react was eroded, reaction was initiated vigorously.