more reactive metals:
potassium (highest reactivity)
sodium
calcium
magnesium
moderate reactive metals:
aluminium
zinc
iron
lead
least reactive metals:
copper
mercury
silver
gold (least reactivity)
Answer: The correct option is A.
Explanation: In a chemical reaction, reactants react to form a number of products.
For the formation of products, the bonds of the individual reactants must be broken and the bonds of the products must be formed.
For example: Formation of water from hydrogen gas and oxygen gas. Reaction follows:

The Bonds of hydrogen and oxygen molecule are broken and new bonds between hydrogen and oxygen atoms are formed to give water molecule.
Answer:
Density = 11.4 g/cm³
Explanation:
Given data:
Density of lead = ?
Height of lead bar = 0.500 cm
Width of lead bar = 1.55 cm
Length of lead bar = 25.00 cm
Mass of lead bar = 220.9 g
Solution:
Density = mass/ volume
Volume of bar = length × width × height
Volume of bar = 25.00 cm × 1.55 cm × 0.500 cm
Volume of bar = 19.4 cm³
Density of bar:
Density = 220.9 g/ 19.4 cm³
Density = 11.4 g/cm³