Answer:
E = 3.825×10⁻¹⁹ J
Explanation:
Wavelength of photon = 5.2 ×10⁻⁷m
Energy of photon = ?
Solution:
Formula:
E = hc/λ
h = plancks constant = 6.63×10⁻³⁴ Js
c = speed of wave = 3×10⁸ m/s
by putting values,
E = 6.63×10⁻³⁴ Js ×3×10⁸ m/s / 5.2 ×10⁻⁷m
E = 19.89×10⁻²⁶ J.m / 5.2 ×10⁻⁷m
E = 3.825×10⁻¹⁹ J
Gravity
Approximately 4.5 billion years ago, gravity pulled a cloud of dust and gas together to form our solar system.
Answer:
Samira's model is incorrect because not all atoms are accounted for
Explanation:
The image of Samira's model has been attached to this answer to enhance the explanation.
What is depicted in that model is rightly regarded as a chemical change. In a chemical change atoms of substances are rearranged as new substances are formed.
However, all atoms in the products must also be found in at least one of the reactants. In this case we have an atom in one of the products that is not accounted for. Hence the model is incorrect.
<span>I think these are the substances that are needed to be categorized into ionic, metallic or covalent: C2H6, Na2O, SiO2, CO2, N2O5, NaNO3, Al, C (diamond) and SO2. Ionic substances are Na2O, SiO2, NaNO3; covalent substances are C2H6, CO2, N2O5, C (diamond); and metallic substances are Al, SO2.</span>
There are two N≡N bonds and three H–H bonds are in reactants.
Given:
The reaction between nitrogen gas and hydrogen gas.

To find:
Bonds on the reactant side
Solution:

Reactants in the reaction = 
The bond between nitrogen atoms in single
molecule = N≡N (triple bond)
Then in two
molecules = 2 N≡N (triple bonds)
The bond between hydrogen atoms in single
molecule = H-H (single bond)
Then in three
molecules = 3 H-H (single bonds)
Product in the reaction =
The bonds between nitrogen and hydrogen atoms in single
molecule = 3 N-H (single bond)
Then in two
molecules = 6 N-H (single bonds)
So, there are two N≡N bonds and three H–H bonds are in reactants.
Learn more about reactants and products here:
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