Answer: (3) silicon
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane 
, propanone 
and water 
The answer for this is 26.6°c
Because the inner course is a totally different thing then the outer course
For this item, we find first the mass of the compound with the empirical formula. That is,
molar mass = 12 (for C) + 1 (for H)
= 13 g/mole
Then, we divide the given mass of the molecular formula by the mass of the empirical formula.
n = 52.07 / 13 = 4
Therefore, the molecular formula is C₄H₄.
Lets let our mass equal 3 on alletals and solve using d=m/v equation
Aluminum
V=3/2.70=1.11
Silver
V=3/10.5=.286
Rhenium
V=3/20.8=.144
Nickel
V=3/8.90=.337
This gives us the following list from largest to smallest Aluminum, Nickel, Silver, and Rhenium
