Answer:
helium , krypton,xenon,radon, argon are noble gasses
Answer:
See the answer below
Explanation:
<em>First, it should be understood that an endothermic reaction is one that absorbs energy in the form of heat from the surrounding.</em> The products of endothermic reactions usually have higher energy than their reactants. Hence, the ΔH° which is referred to as the enthalpy change is usually positive.
<u>Forgetting to cover the coffee-cup calorimeter means some of the heat energy absorbed by the reactants would be exchanged back to the surroundings - a loss.</u> It also means that the enthalpy change would be smaller compared to if the cup had been covered because some of the heat has been lost to the surrounding.
Supposing a temperature of 25 degrees and supposing that all
activity coefficients are 1
pH = -log[H+]
pOH = -log[OH-]
pH + pOH = 14
Thus a pH of 2.50 would mean that the [H+], the concentration of the hydrogen
ion, would be 10^(-2.50)
pH + pOH = 14
pOH = 14 - pH = 14 - 2.5 = 11.5
MOH- levels would be coordinated with pOH
pOH = -log[OH-] ==> [OH-] = [MOH-] = 10^-pOH = 10^-11.5 = 3.2 x 10^-12
Therefore, MOH¯ = 3.2 × 10¯12 M
Answer:
Answer the following questions: What is the composition of air? Answer: Air is composed of nitrogen, oxygen, carbon dioxide, many other gases, water vapour and dust particles. Which gas in the atmosphere is essential for respiration?
Explanation:
Answer:
Neutrons = ( Atomic mass – Atomic number ) ( A–Z )
Protons and Electrons are equal to the atomic number
For example Neon,
Mass number (A) = 20
Atomic Number (Z) = 10
Number of Protons = 10
Number of Electrons = 10
Number of Neutrons = ( A–Z ) = 10
Electronic distribution :
K= 2
L= 8
