Explanation:tr
a) Molar mass of HF = 20 g/mol
Atomic mass of hydrogen = 1 g/mol
Atomic mass of fluorine = 19 g/mol
Percentage of an element in a compound:
Percentage of fluorine:
Percentage of hydrogen:
b) Mass of hydrogen in 50 grams of HF sample.
Moles of HF = 
1 mole of HF has 1 mole of hydrogen atom.
Then 2.5 moles of HF will have:
of hydrogen atom.
Mass of 2.5 moles of hydrogen atom:
1 g/mol × 2.5 mol = 2.5 g
2.5 grams of hydrogen would be present in a 50 g sample of this compound.
c) As we solved in part (a) that HF molecules has 5% of hydrogen by mass.
Then mass of hydrogen in 50 grams of HF compound we will have :
5% of 50 grams of HF = 
An ionic compound is formed between a metal and a non metal. The metal being electropositive can form a cation by transferring the electron to the electronegative non metal that gains the electrons to form an anion. Both the elements try to get a stable octet configuration by the transfer of electrons. The number of electrons lost by metal will be equal to the number of electrons gained by the non metal. Hence, the magnitude of positive charge on the cation will be equal to the magnitude of negative charge on the anion. Therefore, the overall charge on the compound will be 0
So the correct answer is the sum of all charges in the formula for an ionic compound is 0
Answer:
B. a bike braking
Explanation:
It involves friction! Hope this helps!
High tides occur 12 hours and 2 minutes apart do it would be at 6:25 pm
Answer:
333.33 KPa
Explanation:
P1V1=P2V2
p2=P1v1/v2
p2= (2.50 L* 100 kPa)/0.75 L
P2=333.33 kPa
