Answer:
The atom is divisible particle and can be subdivided into smaller particles proton, neutron and electrons was not stated by John dalton.
Explanation:
The postulate of Dalton's atomic theory that atom is indivisible particle and can not be subdivided into smaller particles was later changed because atom can be divided into neutrons, protons and electrons.
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
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
Proton and neutron:
While neutron and proton are present inside the nucleus. 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⁺
Symbol of neutron= n⁰
Mass of proton=1.672623×10⁻²⁷ Kg
Mass of neutron=1.674929×10⁻²⁷ Kg
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron.
Answer:
The amount of drug left in his body at 7:00 pm is 315.7 mg.
Explanation:
First, we need to find the amount of drug in the body at 90 min by using the exponential decay equation:

Where:
λ: is the decay constant = 
: is the half-life of the drug = 3.5 h
N(t): is the quantity of the drug at time t
N₀: is the initial quantity
After 90 min and before he takes the other 200 mg pill, we have:

Now, at 7:00 pm we have:

Therefore, the amount of drug left in his body at 7:00 pm is 315.7 mg (from an initial amount of 400 mg).
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Number of moles of CO2 =
Mass /Ar
= 50.2 / (12 + 32)
1.14 mols
For every 1 mol of gas, there will be
24000 cm^3 of gas
Vol. = 1.14 x 24 dm^3
= 27.36 dm^3
The answer is B charged particles
Answer:
Bacteria are also involved in many processes that are indispensable for our life on Earth. Many of these processes have to do with the recycling (reuse) of chemical elements that have been here since the formation of the planet
Explanation:
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