Answer:
These two numbers are fixed for an element. The mass number tells us the number the sum of nucleons of protons and neutrons in the nucleus of an atom. The atomic number also known as the proton number is the number of protons found in the nucleus of an atom. ... The atomic number uniquely identifies a chemical element.
Explanation:
Answer:
the ion present in the original solution is Ca2+
Explanation:
Precipitation reactions occur when cations and anions in aqueous solution combine to form an insoluble ionic solid called a precipitate.
<u>Step1</u> : If we add Nacl to the solution, there is no precipitate formed
⇒The only possible ion that can form a precipate with Cl- is Ag+; since there is no precipitate formed, Ag+ is not present
<u>Step2</u> : If we add Na2SO4 to the solution, a white precipitate is formed
The possible ions to bind at SO42- are Ca2+ and Fe2+
But the white precipitate formed, points in the direction of Ca2+
⇒This means calcium is present
<u>Step3</u> : If we add Na2CO3 to the filtered solution, there is a precipate formed
Ca2+ will bind also with CO32- and form a precipitate
So the ion present in the original solution is Ca2+
Answer:
C. Yes, if each sample contains 6.02 x 10²³ atoms.
Explanation:
It is possible for each sample to contain 1 mole of each sample if and only if each of the sample if made up of 6.02 x 10²³ atoms.
6.02 x 10²³ atoms is the Avogadro's number. This number is equivalent to a mole of a substance.
- If the amount of matter in the given substance is at least one mole, it is possible that they are made up of one mole each of each substance.
- If they contain lesser amount of atoms, then it is not up to one mole of substance.
- But if it is greater, then, we can have even more than one mole of substance.
A mole is simply a unit of measurement and it is equivalent to 6.02 x 10²³ atoms.
Answer:
two hydrogen can bonded with oxygen to form H2O
Answer:
The answer is sodium which is the element is the most reactive.
