Because your Teeth are composed of calcium, phosphorus, and other minerals. ... But bones are still not as strong as teeth. The hardest part of the human body ,teeth mostly consist of a calcified tissue called dentine. The tooth's dentine tissue is covered in enamel, that hard, shiny layer that you brush.
Answer:
mass of HNO₃ = 0.378 g
Explanation:
Normality = Molarity * number of equivalents
Molarity = Normality/number of equivalents
normality of HNO₃ = 0.30 N, Volume = 20 mL
HNO₃ ionizes in the following way:
HNO₃(aq) ----> H⁺ + NO₃⁻
Therefore, number of equivalents for HNO₃ is 1
molarity of HNO₃ = 0.30/1 =0.30 mol/dm³
Using the formula, molarity = number of moles/volume in liters
number of moles = molarity * volume
Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL
number of moles = 0.006 moles
From the formula, mass = number of moles * molar mass
molar mass of HNO₃ = 63.0 g/mol
mass = 0.006 * 63
mass of HNO₃ = 0.378 g
Answer:
Work done in this process = 4053 J
Explanation:
Mass of the gas = 0.092 kg
Pressure is constant = 1 atm = 101325 pa
Initial temperature 
= 200 K
Final temperature 
= 200 - 85 = 115 K
Gas constant for nitrogen = 297 
When pressure of a gas is constant, volume of the gas is directly proportional to its temperature.
⇒ V ∝ T
⇒ 
= 
------------ ( 1 )
From ideal gas equation 
= m R ------ (2)
⇒ 101325 × = 0.092 × 297 × 200
⇒ = 0.054 
This is the volume at initial condition.
From equation 1
⇒ 
= 
⇒ 
= 0.094
This is the volume at final condition.
Thus the work done is given by W = P [ - ]
⇒ W = 101325 × [ 0.094 - 0.054]
⇒ W = 4053 J
This is the work done in that process.
Answer:
The answer is
<h2>32.4 g</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
volume of aluminum = 12 cm³
Density = 2.70 g/cm³
The mass of aluminum is
mass = 2.7 × 12
We have the final answer as
<h3>32.4 g</h3>
Hope this helps you
