17, to be neutral it has to have equal number of protons and electrons
D = m / V
D = 8.0 g / 25 cm³
D = 0.32 g/cm³
Answer A
Answer:
0.087 moles of water
Explanation:
Given data:
Number of molecules of water = 5.24×10²² molecules
Number of moles of water = ?
Solution:
The given problem will solve by using Avogadro number.
1 mole = 6.022 × 10²³ molecules of water
5.24×10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.87×10⁻¹ mol
0.087 mol
Avogadro number:
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
Answer:
Explanation:
we are given
there are in 0.073 gallons
we can see that there are two non-zero places after decimals
so, there are two siginificant figures
step-1: Change gallons to quarts
we know that
1 gallon = 4 quarts
so, we can write as
step-2: Change into liter
we know that
1 liter = 1.057 quarts
or
step-3: Change into millilitre
we know that
Since, it is asking for only two significant figures
so, we can also write as
...................Answer
