Answer:
option (B) is correct
Explanation:
In case of nuclear reactors first the nuclear energy is emitted due to the nuclear fission of heavy elements.
This nuclear energy is emitted in the form of heat energy.
This heat energy is used to rotate the turbines, that means it is converted in the form of mechanical energy and then finally this mechanical energy is converted into electrical energy.
Jupiter------------------------
The correct answer is option 3. The IUPAC name is Iron(II) sulfide. It is the less stable amorphous form. When this is powdered, it is pyrophoric or it ignites spontaneously in air. It readily reacts with hydrochloric acid producing hydrogen sulfide.
Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
Answer:
Explanation:
Step 1: Given data
- Molarity of the HF solution (M): 0.500 M
- Volume of the solution (V): 750.0 mL
Step 2: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
750.0 mL × 1 L/1000 mL = 0.7500 L
Step 3: Calculate the moles of HF
We will use the following expression.
n = M × V
n = 0.500 mol/L × 0.7500 L = 0.375 mol
Step 4: Calculate the atoms of F in 0.375 moles of HF
We will use the following relationships:
- 1 mole of HF contains 1 mole of atoms of F.
- 1 mole of atoms of F contains 6.02 × 10²³ atoms of F (Avogadro's number).
