Answer:
The table can be used to predict the properties of elements, even those that have not yet been discovered. Columns (groups) and rows (periods) indicate elements that share similar characteristics.
The table makes trends in element properties apparent and easy to understand.
The table provides important information used to balance chemical equations. Atoms are important because they form the basic building blocks of all visible matter in the universe. There are 92 types of atoms that exist in nature, and other types of atoms can be made in the lab. The different types of atoms are called elements. Hydrogen, gold and iron are examples of elements comprised of unique types of a single kind of atom.
Explanation:
The answer is A: Core --> Mantle --> Crust.
Core: The earth's core is the center of the earth, which would ultimately be the deepest. The core is made up of alloy, which is a mixture of many medals, such as iron and nickel.
Mantle: The earth's mantle is the layer between the earths crust and core. Often made of silicate rocks.
Crust: The earth's crust is the outer-most of the three options. Usually made of up different types of rocks.
Answer:
Energy = 7.83 x 10⁻¹⁹ J
Energy = 6.63 x 10⁻¹⁹ J
Explanation:
The energy of a photon in terms of wavelength can be calculated by the following formula:

where,
h = Plank's Constant = 6.63 x 10⁻³⁴ Js
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light
Now, for λ = 254 nm = 2.54 x 10⁻⁷ m:

<u>Energy = 7.83 x 10⁻¹⁹ J</u>
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Now, for λ = 300 nm = 3 x 10⁻⁷ m:

<u>Energy = 6.63 x 10⁻¹⁹ J</u>