Answer:
Can I have the answer choices?
Explanation:
I think I know what it is but I want to be sure
Answer:
A option is correct.
(a) Energy can create a change.
Explanation:
Answer:
45.2%
Explanation:
To calculate the percent of an element in a compound we divide the molar mass of the element by the compound and multiply that by 100
First lets find the molar mass of Fluoride
Looking at the periodic table Fluoride has a molecular mass of 18.998 g
Now we need to find the molecular mass of NaF
Looking at a periodic table, Sodium (Na) has a molecular mass of 22.990g and Fluoride has a molecular mass of 18.998 so NaF has a molecular mass of 22.990(1) + 18.998(1) = 41.988g
Now we divide the mass of fluoride by the mass of sodium fluoride and multiply that by 100 to find the percentage of fluoride that is present in NaF
Mass of Fluoride = 18.998g
Mass of Sodium Fluoride = 41.988g
Percentage of fluoride present in NaF = (18.998g / 41.988g) * 100 = 45.2%
(I) kinetic energy of the boy when he hits the ground =potential energy
I. e ½mv²=mgh where g is 10ms-²
m=34kg, g=10ms² , h=3m
=34×10×3
=1020j
(i i) v²=u²+2gh
v²=0²+2×10×3
= 60
v=sqrt of 60
Because of the common ion effect. Adding a common ion decreases the solubility of the salt which is the intention of a buffer.
