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.
Hope this helps! chemical test is a qualitative or quantitative procedure designed to identify, quantify, or characterise a chemical compound or chemical group. It is used to see if the driver had presence of alcohol or drugs in their system
Answer:
a. Convergent boundary
b. Transform boundary
c. Divergent boundary
Explanation:
Convergent boundary are boundary where tectonic plates collide with each other. This kind of boundary might involve a collision between continental and oceanic plates, continental and continental plates and oceanic and oceanic plates. Generally, convergent boundary are regions for mountainous structures . Example of mountain formed through convergence are mountain Everest and Himalayas .
Transform boundary are boundary where tectonic plates move past each other . This kind of boundary is responsible for the creation of Extensive Fault like the San Andrea Fault.
Divergent boundary are boundary where tectonic plates move away from each other. The diverging movements brings about oceanic ridges. The mid oceanic ridges is where magma rises to the surface to form a new crust. The up welling of this magma causes further separation of this plates.
The picture above illustrate convergent, divergent and transform boundary.
Answer:
a) 
b) 
c) 
Carbon: 
Explanation:
<u>Nitrate</u>
First of all, is important to know that:

a) 10 ppm of nitrate (
) is equal to 
b) The molecular weight of nitrate is 


c) Nitrate has 14 mg of N per 62 mg of NO3

<u>Carbon</u>
Carbonate has 12 mg of C per 60 mg of 
Bicarbonate has 12 mg of C per 61 mg of 


Answer:
The answer to your question is below
Explanation:
Data
mass of CaCO₃ = 155 g
mass of HCl = 250 g
mass of CaCl₂ = 142 g
reactants = CaCO₃ + HCl
products = CaCl₂ + CO₂ + H₂O
1.- Balanced chemical reaction
CaCO₃ + 2HCl ⇒ CaCl₂ + CO₂ + H₂O
2.- Limiting reactant
molar mass of CaCO₃ = 40 + 12 + 48 = 100 g
molar mass of HCl = 2[1 + 35.5 ] = 73 g
theoretical proportion CaCO₃ /HCl = 100 / 73 = 1.37
experimental proportion CaCO₃ /HCl = 155 / 250 = 0.62
As the experimental proportion was lower than the theoretical proportion the limiting reactant is CaCO₃
3.-
Calculate the molar mass of CaCl₂
CaCl₂ = 40 + 71 = 111 g
100 g of CaCO₃ ------------------ 111 g of CaCl₂
155 g of CaCO₃ ----------------- x
x = (155 x 111) / 100
x = 17205 / 100
x = 172.05 g of CaCl₂
4.- percent yield
Percent yield = 142 / 172.05 x 100 = 82.5 %
5.- Excess reactant
100 g of CaCO₃ -------------------- 73 g of HCl
155 g of caCO₃ ------------------- x
x = (155 x 73)/100
x = 133.15 g
Mass of HCl = 250 - 133.15
= 136.9 g