Answer:
Kr, mass number 81, number protons 36.
Explanation:
If the atom has 36 electrons, and it is neutral, it has 36 protons. 36 protons means that this element has atomic number = 36. This is Kr.
Mass number = number protons + number neutrons = 36 + 45 = 81
Answer:
Molarity = 0.79 M
Explanation:
Given data:
Mass of KNO₂ = 67 g
Volume of solution = 1 L
Molarity of solution = ?
Solution:
First of all we will calculate the number of moles.
<em>Number of moles = mass/ molar mass</em>
Number of moles = 67 g / 85.10379 g/mol
Number of moles = 0.79 mol
Molarity:
Molarity = number of moles / volume in L
Molarity = 0.79 mol/1 L
Molarity = 0.79 M
Answer:
Explanation:
Given that,
The specific heat of water is 4.184Jg°C
Mass, m = 600 g
Initial temperature, T₁ = 75.5°C
We need to find the final temperature. We know that heat absorbed is given by :
So, the final temperature is equal to 
.
Answer:
neon is the Noble gas but I have not studied this much
