From periodic table both Argon (Ar) and Neon(Ne) are element in group 18 which are referred to as noble gases.
Noble gases are inert since they have eight (8) valence electrons ( <em>electrons in their outermost shell)</em> which make them stable<em>( neither gain or lose electrons)</em>
Answer: Solving by the method of exponential growth. bacteria = 2 after one hr = 2² = 4 after 2nd hr = 2³ = 8 after 3rd hr = 2⁴ = 16 after 4th hr = 2⁵ = 32