the answer is a chemical element
Answer:
The relative mass of electron is 0.0005
Explanation:
Atoms are the fundamental unit of matter. Every thing in the universe that occupy space and have mass is called matter. we can say that every matter is composed of atoms. while the atom is composed of subatomic particles called electron proton and neutron.
Subatomic particles Relative charge Relative mass
Proton +1 1
Neutron 0 1
Electron -1 0.0005
Electron:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol = e⁻
Mass= 9.10938356×10⁻³¹ Kg
electrical charge on electron= -1.6022 × 10⁻¹⁹ C
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Proton and Neutron:
An atom consist of positively charged central core (nucleus) that is made up of Proton and neutron. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P⁺
electrical charge on proton= +1.6022 × 10⁻¹⁹ C
Mass of proton=1.672623×10⁻²⁷ Kg
Symbol of neutron= n⁰
Mass of neutron=1.674929×10⁻²⁷ Kg
electrical charge on neutron= 0
2NaCN(s) + H₂SO₄(aq) --> Na₂SO₄(aq) + 2HCN(g)
The molar ratio between NaCN : HCN is 2:2 or 1:1
Mass of HCN = 16.7 g
Molar mass of HCN = 1 + 12 + 14 = 27 g/mol
Molar mass of NaCN = 49 g/mol
Therefore, the mass of NaCN is
16.7 g of HCN x 49 g/mol of NaCN / 27 g/mol of HCN = 30.3 grams of NaCN
Therefore, 30.3 grams of NaCN gives the lethal dose in the room.
Answer : The value of for the reaction is -959.1 kJ
Explanation :
The given balanced chemical reaction is,
First we have to calculate the enthalpy of reaction .
where,
= enthalpy of reaction = ?
n = number of moles
= standard enthalpy of formation
Now put all the given values in this expression, we get:
conversion used : (1 kJ = 1000 J)
Now we have to calculate the entropy of reaction .
where,
= entropy of reaction = ?
n = number of moles
= standard entropy of formation
Now put all the given values in this expression, we get:
Now we have to calculate the Gibbs free energy of reaction .
As we know that,
At room temperature, the temperature is 500 K.
Therefore, the value of for the reaction is -959.1 kJ
(a) We know that work is the product of Force and Distance so: (in this
case Distance is negative since going down so –d)
work = force * distance
work = M * (g - g/4) * -d
work = -3Mgd/4 <span>
(b) The work by the weight of the block is simply:</span>
work = Mgd <span>
(c) The kinetic energy is simply equivalent to the
net work, therefore:</span>
KE = net work
KE = Mgd/4 <span>
(d) The velocity is:</span>
v = √(2*KE/M)
Plugging in the value of KE from c:
v = √(2*Mgd / 4M)
<span>v = √(gd / 2) </span>