When wood id burnt, 30 grams of ash are formed due to the chemical changes that occurred.
The missing 370 grams are evaporated into the air where they form other particles and substances.
Answer:
a combination of two or more elements called a compound
MFe: 56 g/mol
..........
56g ----- 1 mol
5g ------- X
X = 5/56 = 0,089 moles of Fe
56g ----- 6,02×10²³ atoms
5g ------- X
X = (5×6,02×10²³)/56
X = 0,5375×10²³ = 5,375×10²² atoms of Fe
:•)
An atom is the smallest unit of matter that has the properties of an element. It is composed of a dense core called the nucleus and a series of outer shells occupied by orbiting electrons. The nucleus, composed of protons and neutrons, is at the center of an atom.
Explanation:
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
