(sample g/1) X (1 mole/40.078(MW of Ca)) = moles of sample (moles of sample)(6.022 x 10^23( no of atoms)/ 1 mole) = # of atoms in a 120 g sample of calcium Avogadro's number=6.022x 10^23 atoms in 1 mole
Atomic mass Ca = 40 a.m.u
1 mole Ca ----------- 40 g
2.5 mols Ca -------- ( mass Ca )
Mass Ca = 2.5 x 40 / 1
Mass Ca = 100 / 1
= 100 g of Ca
hope this helps!
Answer:
M=Molarity
V=volume
change millilitre to litre
so:15ml=0.015 L
:38.5ml=0.0385 L
M1V1=M1V1
M1* 0.015 L= 0.15M*0.0385 L
M1=0.00385
Explanation:
protons have a relative charge of +1, they are located in the nucleus and the carry a positive charge
the electrons are negatively charged and have a charge of -1 . They are found orbiting on the shells .the electrons have a negligible mass of 1 / 1840
the neutrons have no charge they are located in the nucleus of an atom .
