Molecular mass of H2O is: 16+2*1=18
so moles of 40g of H2O is: 40/18=2.22
Answer:
1.750×10^-6 g
Explanation:
we know n is 10^-9. all you have to do is to replace n with 10^-9.
so the answer is
1.750×10^3×10^-9 g
which is equal to 1.750×10^-6 g
if anything is unclear, ask freely.
Answer:
(4) All atoms of a given element must have the same atomic number
Explanation:
Atomic number : It is defined as the number of electrons or number of protons present in a neutral atom.
However, when we talk about the atomic number of the ion, it is not equal to the number of electrons as electron can be gained or loosed.
This is why, more appropriately, the number of the protons which are present in the nucleus of the atom is called the atomic number.
Mass number is the number of the entities present in the nucleus which is the equal to the sum of the number of protons and electrons.
Mass number = Number of protons + Number of neutrons
<u>Thus, atomic number of an element is an unique property of the element and it's atom.</u>
Answer:
2.7 g/cm³
Explanation:
Step 1: Calculate the mass of kerosene
The mass of the full beaker (mFB) is equal to the sum of the masses of the empty beaker (mEB) and the mass of the kerosene (mK).
mFB = mEB + mK
mK = mFB - mEB
mK = 60 g - 20 g = 40 g
Step 2: Calculate the density of kerosene
Density (ρ) is an intrinsic property of matter. It can be calculated as the quotient between the mass of kerosene and its volume.
ρ = m/V
ρ = 40 g/15 cm³ = 2.7 g/cm³
