1.00*10^3
You’d need to lower the exponent because rounding to 3 sig figs changes the 9’s to - 1000. Keep the 0’s.
Answer:
The nuclear charge increases from boron to carbon, but there is no additional shielding( that is no additional shells).
Explanation:
First of all, we must know the electron configuration of carbon and boron.
Boron- 1s2 2s2 2p1
Carbon- 1s2 2s2 2p2
Moving from boron to carbon, the effective nuclear charge increases without a corresponding increase in the number of shells. Remember that shielding increases with increase in the number of intervening shells between the outermost electron and the nucleus. Since there isn't an increase in shells, boron experience a lower screening effect.
From
Zeff= Z- S
The Z for carbon is 6 while for boron is 5 even though both have the same number of screening electron S(4 screening electrons). Hence it is expected the Zeff(effective nuclear charge) for boron will be less than that of carbon.
0.0788 will be the number of moles of silver in coin.
<h3><u>How to find the number of moles?</u></h3>
A mole is the mass of a material made up of the same number of fundamental components. Atoms in a 12 gram example are identical to 12C. Depending on the material, the fundamental units may be molecules, atoms, or formula units.
A mole fraction shows how many chemical elements are present. The value of 6.023 x 10²³ is equivalent to one mole of any material (Avagadro's number). It can be used to quantify the chemical reaction's byproducts. The symbol for the unit is mol.
The number of moles formula is denoted by the following expression:
Number of moles = Mass of substance/mass of one mole
To view more about number of moles, refer to:
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B) The velocity of the car reduced from 50k/m over one min.
<span>Use the Ideal law Equation :
P.V= n.R.T
V = 0.5 L
P = 1.0 atm
</span><span>R= 0.0821 L*atm/mol*K
</span>
<span>n = R*T/P*V
</span><span>P*V= n*R*T
</span>
1.0 * 0.5 = n *<span>0.0821*298
0,5 = n* 24.4658
n = 0,5 / 24.4658
n =0.0204 moles
</span>
