Answer:
Explanation:
Molar mass of Argon
= 35.96755 x .00337 + 37.96272 x .00063 + 39.96240 x .99600
= .12121 + .0239165 + 39.80255
= 39.95
Molar mass of silicon
27.97693 x .9223 + 28.97649 x .0467 + 29.97376 x .0310
= 25.803 + 1.35320 + .929
= 28.08
b )
No of atoms of Si in 78.2 g = 78.2 x 6.02 x 10²³ / 28.08
= 16.76 x 10²³ .
c )
42 Ar / 40 Ar = 1.05006
42 Ar / 39.95 = 1.05006
42Ar = 41.95
2 )
C₁₆H₁₅F₂N₃O₄S
Mol weight = 16 x 12 + 1 x 15 + 2 x 19 + 3 x 14 + 4 x 16 + 32
= 192 + 15 + 38 + 42 + 64+ 32
= 383
No of molecules = .078 x 6.02 x 10²³ / 383
= 1.226 x 10²⁰ molecules .
Answer:
He developed the concept of concentric electron energy levels
Explanation:
Before Bohr's model, Rutherford's model was proposed. This model explains most of the properties of the atom but failed to explain the stability of the atom.
As per Rutherford's model, electrons revolve around the nucleus in the orbit.
But revolving electron in their orbit around nucleus would give up energy and so gradually move towards the nucleus and therefore, eventually collapse.
Bohr's proposed that the electrons around the nucleus move orbit of fixed energy called "stationary states". Electrons in these stationary states do not radiate energy.
Therefore, proposal of concentric electron energy levels refine the atomic models.
Answer:
K₂CO₃
Explanation:
Given parameters:
Number of moles of K = 0.104mol
Number of moles of C = 0.052mol
Number of moles of O = 0.156mol
Method
From the given parameters, to calculate the empirical formula of the elements K, C and O, we reduce the given moles to the simplest fraction.
Empirical formula is the simplest formula of a compound and it differs from the molecular formula which is the actual formula of a compound.
- Divide the given moles through by the smallest which is C, 0.052mol.
- Then approximate values obtained to the nearest whole number of multiply by a factor to give a whole number ratio.
- This is the empirical formula
Solution
Elements K C O
Number of moles 0.104 0.052 0.156
Dividing by the
smallest 0.104/0.052 0.052/0.052 0.156/0.052
2 1 3
The empirical formula is K₂CO₃
Answer:
I think it's 4
Explanation:
but I don't really remember the water cycle
The answer is B. Acid turns blue litmus paper to red
