Answer:
Explanation:
= Mass of metal = 19 g
= Specific heat of the metal
= Temperature difference of the metal = 
V = Volume of water = 150 mL = 
= Density of water = 
= Specific heat of the water = 4.186 J/g°C
= Temperature difference of the water = 
Mass of water
Heat lost will be equal to the heat gained so we get
The specific heat of the metal is .
Atomic number should be the answer
Answer:
C
Explanation:
A fuel cell uses both hydrogen and oxygen as fuels. At the cathode oxygen is reduced to water according to the equation
O2+4H^+ +4e ------>2H2O
And hydrogen is oxidized at the anode:
2H2------>4H^+ +4e
Fuel cells produce only water as a by product hence they are environment friendly
Answer:
is the isotopic notation of the atom
Explanation:
The isotope notation is:
<em>Where a is the mass number = Number of protons + Number of neutrons</em>
<em>b is atomic number = Number of protons</em>
The atomic number define the nature of the atom, the element with atomic number = 15 is phosphorus, P:
a = 15 protons + 16 neutrons = 31
b = 15
is the isotopic notation of the atom.
1 mole of any substance contains Avogadro's number.
So, 1 mole of O2= 6.023x10^23 molecules
3 mole of O2= 6.023x10^23x3 molecules
= 1.8069x10^24 molecules
Each molecule of Oxygen has 2 atoms.
therefore,
1.8069x10^24 molecules= 1.8069x10^24 x 2 atoms
= 3.6138x10^24 atoms.
