Nuclear fusion in the sun involves hydrogen (H) atoms
combining to form helium (He). A student claims that since the atmosphere
contains hydrogen, any fusion reaction on Earth would result in an uncontrolled
chain reaction. What is wrong in the student’s reasoning is that the uncontrolled
chain reactions can only happen during nuclear fission.
Elements which composed of an equal amount of three components protons, neutrons and electrons are considered neutral elements. example of neutral elements are hydrogen, helium, lithium and beryllium...
Answer: 16700 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed = ?
m = mass of sand = 2 kg
c = heat capacity = 
Initial temperature =
= 
Final temperature=
= 
Change in temperature ,
Putting in the values, we get:


16700 J of energy must be added to a 2-kilogram pile of it to increase its temperature from 40°C to 50°C
Answer:
Boron and Aluminium
Explanation:
Boron and Aluminium are present in Group 13 of the modern periodic table. Group 13 (IUPAC System) can also be referred to as Group III-A. Logically, Boron and Aluminum can't be placed alongwith elements such as Yttrium as they don't exhibit properties of a transition metal.