Assuming we have a 100g sample, the mass of each element is as follows:
C: 74 g
H: 7.4 g
N: 8.6 g
O: 10 g
Next, we calculate the moles of each by dividing the mass of each element by its molar mass:
C: (74 / 12) = 6.17
H: (7.4 / 1) = 7.4
N: (8.6 / 14) = 0.61
O: (10 / 16) = 0.625
Now, we take the smallest value to determine the ratio:
C: 10
H: 12
N: 1
O: 1
Thus, the empirical formula can be expressed as
C10H12NO
Answer:
The correct options include choice 2, 3, and 6.
Explanation:
Density is identified as the mass of a substance per unit volume occupied by that substance.
The density remains constant for a given substance, regardless of variations in mass and volume hence it is considered an intensive property.
2. 20.2 g of silver in 21.6 mL of water and 12.0 g of silver also in 21.6 mL of water.
3. 15.2 g of copper in 21.6 mL of water and 50.0 g of copper in 23.4 mL of water.
6. 11.2 g of gold in 21.6 mL of water and 14.9 g of gold in 23.4 mL of water.
The same metals in both instances will yield consistent densities due to the fixed density of the metal.
Your Question: There are two kinds of elements that didn't appear on the periodic table until after 1892. What kinds are they and why do you think it took so long to discover them?
The Answer: The insights of Moseley led chemists to further refine the periodic table and uncover additional gaps, indicating that several new elements, specifically with atomic numbers 43, 61, 72, and 75, remained undiscovered. These elements were later identified as technetium, promethium, hafnium, and rhenium, respectively.
Explanation: Physicist Henry Moseley used x-rays to determine the atomic number of elements, which facilitated a more accurate organization of the periodic table. His life and the discovery of the correlation between atomic number and x-ray frequency, known as Moseley's Law, are significant to note.
Remember to consult study guides, lessons, and notes; hard work is essential for success. Good Luck!
According to the sign convention, a negative Δ
indicates that the reaction is exothermic, resulting in a loss of heat and a reduction in temperature.
The amino acids classified under the first group include alanine, aspartate, and glutamate, whereas those in the second group consist of glycine, valine, proline, leucine, isoleucine, methionine, serine, threonine, cysteine, asparagine, glutamine, phenylalanine, tryptophan, tyrosine, lysine, arginine, and histidine.
