Answer:
8.99×10^-7m
Explanation:
The wavelength can be calculated using the expression below
E=hcλ
Where E= energy= 2.21 x 10^-19 J.
C= speed of light= 3x10^8 m/s
h= planks constant= 6.626 × 10^-34 m2 kg / s
E=hcλ
λ= E/(hc)
Substitute for the values
λ=( 2.21 x 10^-19 )/(6.626 × 10^-34 × 3x10^8 )
= 8.99×10^-7m
Radioactivity another name for radioactive decay. Radioactivity refers to particles emitted from nuclei as a result of nuclear instability.
The order would be coefficient, law of conservation of mass, products, and reactants respectively.
<h3>Word matching</h3>
The number written in front of a chemical symbol in an equation is called a coefficient.
The total mass of a system being unchanged is known as the law of conservation of mass
The substances made in chemical reactions are called products.
The starting materials in chemical reactions are called reactants.
More on reactions can be found here: brainly.com/question/17434463
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It is a physical change because only the states as being changes, not the actual bonds in the compound.
