Answer: A metallic bond is a type of chemical bond formed between positively charged atoms in which the free electrons are shared among a lattice of cations. In contrast, covalent and ionic bonds form between two discrete atoms. Metallic bonding is the main type of chemical bond that forms between metal atoms.
Explanation:
NOT MY WORDS! I HOPE THIS HELP!!!!!
 
        
                    
             
        
        
        
Zeff = Z - S
Here, Z is the number of protons in the nucleus, that is, atomic number, and S is the number of nonvalence electrons. 
For boron, the electronic configuration is 1s₂ 2s₂ 2p₄
Z = 5, S = 2 
Zeff = 5-2 = +3
For O, electronic configuration is 1s₂ 2s₂ 2p₄
Z = 8, S = 2
Zeff = 8-2 = +6
Hence, the correct answer is second option, that is, +3 and +6, the Zeff of boron is smaller in comparison to O, thus, boron exhibits a bigger size than O. 
 
        
             
        
        
        
Explanation:
3 little bones in ear takes that vibration and empowers them. Then they transfer the vibrations to next part of ear.
 
        
             
        
        
        
In order to compute the mass of each solute in the sample, we simply multiply the percentage mass of each solute with the total mass of the solution. This is ad such:
Mass (NaCl) = 0.0486 x 294
Mass (NaCl) = 14.29 grams
Mass(Na₂CO₃) = 0.0754 x 294
Mass(Na₂CO₃) = 22.17 grams
        
             
        
        
        
Answer:
ΔG = - 442.5  KJ/mol    
Explanation:
Data Given
delta H = -472 kJ/mol
delta S = -108 J/mol K
So,
delta S = -0.108 J/mol K
delta Gº = ?
Solution:
The answer will be calculated by the following equation for the Gibbs free energy
                     G = H - TS
Where
G = Gibbs free energy
H = enthalpy of a system (heat 
T = temperature
S = entropy
So the change in the Gibbs free energy at constant temperature can be written as
                 ΔG = ΔH - TΔS . . . . . . (1)
Where
ΔG = Change in Gibb’s free energy
ΔH = Change in enthalpy of a system
ΔS = Change in entropy
if system have standard temperature then
T = 273.15 K
Now,
put values in equation 1
                   ΔG = (-472 kJ/mol) - 273.15 K (-0.108 KJ/mol K)
                  ΔG = (-472 kJ/mol) - (-29.5 KJ/mol)
                  ΔG = -472 kJ/mol + 29.5 KJ/mol
                  ΔG = - 442.5  KJ/mol