Please help me out with these 2 questions. number 5 and 6. Please explain the co
ID: 714841 • Letter: P
Question
Please help me out with these 2 questions. number 5 and 6. Please explain the concept. I will be very grateful. thanks
Student Login ×YM Inbox (2223), pushche x D Living with theLab-EN-XyD x ENGR 120 Living with the Lab lear x C Cheg Study Gueded l Not secure / www2.latechedu/-kcorbett/LwTLENGR120/homework/Ho 1.pdf 5. How many atoms are in a block of copper with the dimensions shown below? (HINT: 2.54cm i) #atoms-1.39 x 1024 atoms o.Sin t 1in 2in 6. You have a small cylindrical piece of aluminum with a height of 3cm and a diameter of 0.5cm. About how many valence electrons does the cylinder contain? (Hint: One atom of aluminum has three valence electrons.) # Valence Electrons-1065 x 1023 e.Explanation / Answer
5 . Area of the block = l × b × h
l = 2.54cm × 2in = 5.08 cm
b = 1in = 2.54cm and h = 2.54/2 = 1.27cm
Area = 5.08×2.54×1.27 = 16.39 cm^3 = 16.49ml (as 1ml = 1cm^3) .
Density of copper = 8.96 g/ml
As density = mass/volume
Then Mass of copper = density × volume = 8.96 × 16.39 = 146.85 g .
63.55 g (atomic mass) of copper has atoms = 6.023 × 10^23 atoms
Then 146.85 g of copper will have atoms = 6.023×10^23×146.85 /63.55 = 13.92 ×10^23 = 1.39×10^24.