Answer:
1. Rutherford did the scattering experiment and observed that some of the rays bounce back. He concluded that there is a mass in which positive charge is concentrated. This marks the discovery of nucleus.
2. J.J Thomson discovered electrons by conducting cathode ray experiment.
3. Dalton postulated that matter is made up of small particles caled atoms
One thing that does not change is the chemical composition of water, which is still H2O. And maybe mass, if all of the particles remain inside the beaker, which was never mentioned in the question so I am not sure.
1.38 moles of oxygen
Explanation:
Thermal decomposition of Lead (II) nitrate is shown by the balanced equation below;
2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂
The mole ration of Lead (II) nitrate to oxygen is 2: 1
Therefore 2.76 moles of Lead (II) nitrate will lead to production of? moles of oxygen;
2: 1
2.76: x
Cross-multiply;
2x = 2.76 * 1
x = 2.76 / 2
x = 1.38
Mass number = protons + neutrons
mass number = 5 + 7
mass number = 12
Answer:
<u>It increases by a factor of four</u>
Explanation:
Boyle's Law : At constant temperature , the volume of fixed mass of a gas is inversely proportional to its pressure.
pV = K.......(1)
pV = constant
Charles law : The volume of the gas is directly proportional to temperature at constant pressure.
V = KT
or V/T = K = constant ....(2)
Applying equation (1) and (2)
According to question ,
T2 = 4 (T1)
V2 = V1
Put the value of T2 and V2 , The P2 can be calculated,
V1 and V1 cancel each other
T1 and T1 cancel each other
We get,
or
P2 = 4 P1
So pressure increased by the factor of four
