Isotopes are two or more of the same type of element. They are different because they all have a different relative atomic mass.
Answer:
Part A: 27.8 L; Part B: 0.500 mol
Explanation:
Part A
For an ideal gas, we can use the equation:
PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
In the beggining:
P*48.0 = 1.90*RT
P/RT = 1.90/48.0
P/RT = 0.03958
For constants pressure and temperature, after 0.800 mol of gas leaks out: n = 1.90 - 0.800 = 1.10 mol
PV = 1.10*R*T
P/RT = 1.10/V
0.03958 = 1.10/V
V = 1.10/0.03958
V = 27.8 L
Part B
In the beginning
PV = nRT
P*70.0 = 2.00*RT
P/RT = 2.00/70.0
P/RT = 0.02857
After the gas leaked out:
PV = nRT
P*17.5 = nRT
P/RT = n/17.5
0.02857 = n/17.5
n = 0.500 mol
<u>Answer:</u>
By 1700, 13 elements had been discovered and isolated by the Scientists.
Option (a)
<u>Explanation:</u>
- The copper, gold and silver are the elements which have been known from thousands of years. In the early days of 1700, the scientist discovered only 12 elements, later on one more element was discovered.
- Later in the era of 1800, the scientist research and find new elements, where they organize it methodically, according to the physical and chemical properties.
- After a long research in 1900 scientist discovered more than 80 elements.
Answer:
It is B
Explanation:
I was able to find my school notes and double-check. I hope you have a nice day!
Answers:
Most of the world’s energy comes from what three sources?
Oil, coal, and gas.
These energy sources are called <u>fossil</u> fuels and they are <u>non-renewable</u> resources.
Fuel type: oil
How it's formed: from the remains of ancient marine organisms
Its uses: transportation, industrial power, heating and lighting, lubricants, petrochemical industry, and use of by-products
Fule type: coal
How it's formed: when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial
Its uses: electricity generation, metal production, cement production, chemical production, gasification, and other industrial uses
Fuel type: gas
How it's formed: decomposed organic matter mixed with mud, silt, and sand on the seafloor
Its uses: heating & cooling buildings, cooking foods, fueling vehicles, and electricity generation