Answer:
Certain things we think of as hard work, such as writing an exam or carrying a heavy load on level ground, are not work as defined by a scientist. The scientific definition of work reveals its relationship to energy—whenever work is done, energy is transferred.
For work, in the scientific sense, to be done, a force must be exerted and there must be motion or displacement in the direction of the force.
Answer:
Chemical Change
Explanation:
Physical change normally mean that the change can revert back to its orginal state, which in this case that is not possible therfore it is a chemical change.
Since a water molecule is H2O, you would divide 126 hydrogen molecules by 2, and you would get 63. That means you have 63 double hydrogen molecules, and 58 oxygen molecules to pair up with them. So that means you could have 58 molecules of water, with 5 double hydrogen molecules, so basically 10 extra molecules of hydrogen along with the H2O molecules. Hope I helped! :)
Answer:
3.025eV
Explanation:
Energy of a photon is given by
E=hν
Where h is the Planck's constant
And ν represents the frequency of the photon .
Now for violet light wavelength λ=410nm= 410x10^-9m
By using the formula ν=c/λ
where c represents speed of light I.e 3 x 10^8 m/s
Calculating energy of violet photon we have
E=hc/λ
h=6.626 x 10^-34 J.s
On inserting the value in the formula , we get
E= 4.848 x 10^-19 Joules
To convert it into electron volts we need to divide it by 1.602 x10^-19.
The final result what we have is E=3.026eV.
Note: the result calculated is according to the above value . result may vary according to the values taken .
Answer:
2.30 × 10⁻⁶ M
Explanation:
Step 1: Given data
Concentration of Mg²⁺ ([Mg²⁺]): 0.039 M
Solubility product constant of Mg(OH)₂ (Ksp): 2.06 × 10⁻¹³
Step 2: Write the reaction for the solution of Mg(OH)₂
Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)
Step 3: Calculate the minimum [OH⁻] required to trigger the precipitation of Mg²⁺ as Mg(OH)₂
We will use the following expression.
Ksp = 2.06 × 10⁻¹³ = [Mg²⁺] × [OH⁻]²
[OH⁻] = 2.30 × 10⁻⁶ M
