i may be wrong but Use the normal boiling points: propane, C3H8, –42.1˚C; butane, C4H10, –0.5˚C; pentane, C5H12, 36.1˚C; hexane, C6H14, 68.7˚C; heptane, C7H16, 98.4˚C; to estimate the normal boiling point of octane, C8H18.
Answer:
option b = atomic number
Explanation:
The atomic number of silver is 47. Its isotopes range from Ag⁹³ - Ag¹³² . The naturally occurring silver is made up of two stable isotopes i.e ₄₇Ag¹⁰⁷ and ₄₇Ag¹⁰⁹. The percentage of Ag¹⁰⁷ is 51.84% so it is more abundant than ₄₇Ag¹⁰⁹. Their atomic masses are different but the atomic number is same i.e 47.
A neutral atom have equal number of protons and neutrons. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example in case of silver 47 protons and 47 electrons are present. The number of protons or number of electrons are the atomic number of an atom while the number of protons and number of neutrons are the mass number of an atom. Every atom consist of nucleus or a positive center. The protons and neutrons are present with in the nucleus while electrons are present out side the nucleus. All these three subatomic particles construct an atom.
Co= 59g
S=32g
59+32=91g/mol
the molarity of KCl solution prepared by dissolving 0.898 mole of KCl in 250 ml water is calculated using the below formula
molarity= moles/volume in liters
moles= 0.898 moles
volume in liters= 250/1000 =0.25 liters
molarity is therefore= 0.898/0.25= 3.592 M
The return date is 3 0 4
<u>Explanation</u>
In the letter, it is mentioned that the school will reopen after 29th of April. Thus, the tentative date of the school to reopen is 30th of April. The three digit return date is 3 0 4
3 0 4 because 30 is the date when the school will reopen and 4 is the month i.e., april when the school will reopen.
