There are 5 valence electrons in a atom of phosphorus.
Answer : The energy required to heat of 1.50 kg iron is, 
Explanation :
Formula used :
or,
where,
Q = heat required = ?
m = mass of iron = 1.50 kg = 1500 g
c = specific heat of iron = 
= initial temperature = 
= final temperature = 
Now put all the given value in the above formula, we get:
Therefore, the energy required to heat of 1.50 kg iron is,
A strong acid is an acid that ionizes completely in an aqueous solution. A strong acid will always loose a proton (A H+) when dissolved in H2O. In other words, a strong acid is always on its toes and quite efficient in giving off protons. A weak acid is one that ionizes partially in a solution.There you go, I hope this helped.
The answer to your questions are
Question 1 - D - stationary
Question 2 - C - I'm not 100% sure
Question 3 - A - the northern subtropical jet stream
Question 4 - A - cold
