Answer:
The correct answer is option c.
Explanation:
Formula used to determine an average atomic mass :

Mass of isotope Sb-121 = 120.904 amu
Fractional abundance of Sb-121 = 57.21% = 0.5721
Mass of isotope Sb-123 = 122.904 amu
Fractional abundance of Sb-123 = 42.79% = 0.4279
Average atomic mass of Sb:

Answer:
D. It is a chemical reaction because the total mass remains the same when new substances are formed.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
While in case of nuclear reaction small change in mass take place.
First you need to know the different between an ionic and covalent bond. An ionic bond is the pairing of a metal and non-metal element. A covalent bond is the pairing of 2 nonmetals.
Metals are the elements at the left of the periodic table while non-metals are the elements at the right of the periodic table.
You should also know the diatomic (di means 2) molecules also known as the fab 7. These molecules will always form covalent bonds. These molecules are hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. With the subscripts, these molecules would be written as H ₂, N ₂, O ₂, F ₂, Cl ₂, Br ₂, and I ₂.
1 and 3 only because metal are easily to loss electron while non metal are difficult to loss electron that's why it called heavy elements.
Answer:
6 moles of NaCl are needed to make 3.0 liters of a 2.0 M NaCl solution.
Explanation:
A 2M solution means that there are 2 moles of solute (NaCl in this case) in 1 liter of solution:
1 L solution-----2 moles of NaCl
3 L solution----x= (3 L solutionx2 moles of NaCl)/1 L solution= <em>6 moles of NaCl</em>