Answer:
C
Explanation:
This is a correct answer i think soo
Answer:
He developed the concept of concentric electron energy levels
Explanation:
Before Bohr's model, Rutherford's model was proposed. This model explains most of the properties of the atom but failed to explain the stability of the atom.
As per Rutherford's model, electrons revolve around the nucleus in the orbit.
But revolving electron in their orbit around nucleus would give up energy and so gradually move towards the nucleus and therefore, eventually collapse.
Bohr's proposed that the electrons around the nucleus move orbit of fixed energy called "stationary states". Electrons in these stationary states do not radiate energy.
Therefore, proposal of concentric electron energy levels refine the atomic models.
Answer: Wheel and Axle
Both of these work together to form a simple machine. You can't have one without the other.
If you try to turn just the axle itself, then you'll find it takes a lot of work. This is because the inertia of the axle wants to keep the object at rest. Also, you won't have a lot of torque due to the small radius compared to what a doorknob can offer.
Using a doorknob is like putting a (steering) wheel on an axle. This increases the radius and therefore increases the torque. You put in less work into the system and get more out of it.
Answer:
100 cm³
Explanation:
Hi there!
Subtract:
400 cm³ - 300 cm³
= 100 cm³
Therefore, the volume of the object is 100 cm³.
I hope this helps!
Answer:
10.1 g of Al are formed
Explanation:
The reaction is:
2AlCl3 --> 2Al + 3Cl2
So 2 moles of aluminun chloride decompose into 2 moles of Al and 3 moles of chlorine.
Ratio is 2:2.
Let's convert the mass of salt into moles (mass / molar mass)
50 g / 133.34 g/mol = 0.374 moles.
As the ratio is 2: 2, if I have 0.374 moles of salt, I would produce the same amount of Al, just 0.374.
Let's convert the moles to mass
(Mol . molar mass)
0.374 mol . 26.98 g / mol = 10.1 g of Al are formed
Ξ
