Answer: 11.25 J
Explanation: Kinetic energy is expressed as the product of mass and the squared of velocity divided by 2.
Its d its the only one that makes sense
Answer : The correct options are,
and 
Explanation :
Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.
Option A reaction : 
It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.
Option B reaction : 
It is an example of single displacement reaction.
Option C reaction : 
It is an example of combination reaction because in this reaction two reactants react to give a single product.
Option D reaction : 
It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.
Option E reaction : 
It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.
Hence, the options B and E are single displacement reactions.
Answer:
2.5 g/cm3 .
Explanation:
Density is mass in grams over volume in cubic centimeters. So it is 25 g 10 cm 3 =2.5 g/cm 3 The unit is grams per cubic centimeter. NB - density can also be kilograms over cubic meters Hope this helps!