Answer:
600 years ago
Explanation:
it was first recorded by England's Sir Francis Bacon (1561-1626)
Answer:
1.51×10²³ atoms.
Explanation:
From the question given above, the following data were obtained:
Mass of Calcium (Ca = 10 g
Number of atom of Calcium (Ca) =?
The number of atoms present in 10 g of Ca be obtained as follow:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.
1 mole of Ca = 40 g.
Now, if 40 g of Ca contains 6.02×10²³ atoms.
Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.
Thus, 10 g of calcium contains 1.51×10²³ atoms.
Answer:
a is unbalanced and bcd is balanced
Assuming the complete question is;
Consider the balanced equation below;
4NH3 + 3O2 = 2N2 +6H2O
What is the mole ratio of NH3 to N2;
From the balanced equation; the mole ratio of NH3 to N2 is 4:2.
The mole ratio is the ratio of moles of one substance to the number of moles of another substance in a balanced equation. In the above equation; 4 moles of ammonia requires 3 moles of oxygen to produce two moles of nitrogen and six moles of water.