Answer:
Oxygen : 6.3
Carbon : 4.3
Explanation:
The steps to calculate the Zeff is :
1) Write the electronic configuration.
Carbon: 1s2 2s2 2p2
Oxygen: 1s2 2s2 2p4
2) there are two core electrons in each atom and four in carbon and six in oxygen.
(1s) (2s2p)
3) as mentioned the shielding of electrons within the same shell is negligible.
4) for electron of s or p orbital the shielding contribution by the electrons having a principal quantum number less by one would be 0.85 each. And all electrons further left would contribute an amount of 1.0 each.
5) For oxygen:
Zeff = Z - S
S = 2X0.85 = 1.7
Zeff = 8- 1.7 = 6.3
For carbon
Zeff = Z - S
S = 2X0.85 = 1.7
Zeff = 6- 1.7 = 4.3
Answer:
m = 176.04 g .
Explanation:
Hello there!
In this case, according to the mole-mass relationships, which are based off the mass of one mole of any compound via the molar mass, it is possible to realize that the molar mass of carbon dioxide is 44.01 (12.01+16*2) g/mol, and therefore, the mass in grams of 4.00 moles of this compound are calculated as shown below:
Best regards!
<em>Answer:</em>
<em>242 gram</em> of HF will be required for complete rex.
<em>Balance chemical equation:</em>
SiO2 + 4HF → SiF4 + 2H2O
<em>Data given</em>
mass of SiO2 = 182g
molar mass of SiO2=60.08
moles of SiO2 = mass/molar mass = 182/60.08 =3.02 moles
From balance chemcial equation
SiO2 : HF
1 : 4
3.02 = 4 × 3.02 = 12
mass of HF= no. of moles × molar mass
mass of HF = 12.08×20 =<em> 242 g</em>
Answer would be B. I provided work on an image attached. Message me if u have any other questions on how to do it
You have to convert the mass from g to kg since the unites for a joule is kgm²/s². When you do this you should have E=(1.0×10⁻⁷ kg)×(3.00×10⁸ m/s)². With that E=9.00×10⁹J which equals 9.00×10⁶kJ.
I hope this helps. Let me know if anything is unclear.