1.) A compound is a substance that originates from two or more separate elements. It shares some similarities with a mixture.
2.) A compound has quite different properties from which it was formed. It also cannot be separated easily. Compounds are formed by chemical reactions.
3.) A pure substance has a constant composition and has consistent properties. It can be a compound or an element, but its composition is constant.
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I think its chlorine Im not positive but im 99.9 precent shure
Answer:
241 nm, it is UV light range
Explanation:
The minimum energy needed required to break the oxygen-oxygen bond = 495 kJ/mol
Energy needed for 1 molecule of oxygen = 495 × 10³ J / avogadro's constant = 495 × 10³ J / ( 6.02 × 10²³) = 8.223 × 10⁻¹⁹ J
Energy = hv
where h = Planck constant = 6.626 × 10 ⁻³⁴ m²kg/s and v = frequency
c speed of light = vλ
c / λ = v
E = hc / λ
λ = hc / E = (6.626 × 10 ⁻³⁴ m²kg/s × 3.0 × 10 ⁸ m/s) / (8.223 × 10⁻¹⁹ J) = 2.41 × 10⁻⁷m = 241 nm
UV light wavelength is between 400 nm - 10 nm
Answer:
Two methods which help us to conserve water are:
Sprinkler irrigation system: this irrigation has an arrangement of vertical pipes with rotating nozzles on the top. It is more useful in the uneven and sandy land where sufficient water is not available.
Drip irrigation system: this irrigation system has an arrangement of pipes or tubes with very small holes in them to water plants drop by drop just at the base of the root. It is very efficient as water is not wasted at all.
Answer:
Two half lives.
Explanation:
It is known that the decay of isotopes and radioactive material obeys first order kinetics.
Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
That means for a sample 100% to decay to 50 % it will take one half-life, and to decay the remaining 50% to 25% it will take another half-life.
So, for a sample has 25% parent and 75% daughter it will have two half-lives.
