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Citrus2011 [14]
3 years ago
5

What protects living things from too much ultraviolets radiation?

Chemistry
1 answer:
mixas84 [53]3 years ago
8 0
The ozone layer of the Earth's atmosphere is what protects living things from too much ultraviolet radiation, if that's what you're asking about. 
You might be interested in
Acetone is one of the most important solvents in organic chemistry. It is used to dissolve everything from fats and waxes to air
Yanka [14]

Answer: a. 79.6 s

b. 44.3 s

c. 191 s

Explanation:

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

t_{\frac{1}{2}}=\frac{0.693}{8.7\times 10^{-3}s^{-1}}=79.6s

b) for completion of 32% of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-32}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{68}

t=44.3s

c) for completion of 81 % of reaction  

t=\frac{2.303}{k}\log\frac{100}{100-81}

t=\frac{2.303}{8.7\times 10^{-3}}\log\frac{100}{19}

t=191s

4 0
2 years ago
How many neutrons does an atom of Uranium 240?
qwelly [4]

Answer:

Number of neutrons is equal to 148.

4 0
1 year ago
When molten sulfur reacts with chlorine gas, a vile-smelling orange liquid forms that has an empirical formula of SCl. The struc
egoroff_w [7]

Answer:

The structure is shown below.

Explanation:

The formal charge (FC) is the charge that is more close to the actual charge in the real molecules and ions. It can be calculated based on the number of valence electrons (V), the shared electrons (S) and the electrons in the lone pairs (L) by the equation:

FC = V - (L + S/2)

Sulfur is in group 16 of the periodic table, so it has 6 valence electrons, and chlorine is from group 17 of the periodic table, and so it has 7 valence electrons. Chlorine can share only one electron, so it is stable. Sulfur can expand its octet (because it's from the third period) and can have more than 8 electrons when stable.

The possible formulas, from the empiric one, are:

SCl, S₂Cl₂, and S₃Cl₃.

To have FC = 0, chlorine must done only one bond, because S = 2, and L = 6, so:

FC = 7 - (6 + 2/2) = 0

So, it can not be the central atom of a structure. In the SCl, it will hav only a simple bond, so for sulfur, S = 2, and L = 4 (only the lone pairs are counted)

FC = 6 - (4+ 2/2) = +1

For S₂Cl₂, the two sulfurs must be bonded to a simple bond, and each one to one chlorine, thus, for both od them S = 4, and L = 4. so

FC = 6 - (4 + 4/2) = 0

So, it is the correct structure. The lewis structure represents the bonds by lines and the lone pairs of electrons by dots, and it is shown below.

3 0
2 years ago
Balance the following reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coeffici
irina1246 [14]

Answer:

                     2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O

Explanation:

Step 1: Write the unbalanced chemical equation,

                          C₄H₁₀ + O₂ → CO₂ + H₂O

Step 2: Balance Carbon  Atoms;

As there are 4 carbon  atoms on left hand side and 1 carbon atoms on right hand site therefore, to balance them multiply CO₂ on right hand side by 4 i.e.

                            C₄H₁₀ + O₂ → 4 CO₂ + H₂O

Step 3: Balance Hydrogen Atoms;

There are 10 hydrogen atoms on left hand side and 2 hydrogen atom on right hand site therefore, to balance them multiply H₂O on left hand side by 5 i.e.

                            C₄H₁₀ + O₂ → 4 CO₂ +  5 H₂O

Step 4: Balance Oxygen Atoms:

Now there are 2 oxygen atoms in reactant side and 13 in product side. So, multiply O₂ by 6.5 i.e.

                            C₄H₁₀ + 6.5 O₂ → 4 CO₂ + 5 H₂O

Step 5: Remove fraction coefficients as,

Multiply whole equation by 2 to get rid of fractions i.e.

                            2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O

7 0
2 years ago
A hypothetical element x has 3 naturally occurring isotopes: 41.20% of 21x, with an atomic weight of 21.016 amu, 50.12% of 22x,
iogann1982 [59]
The average atomic weight is calculated by adding up the products of the percentage abundance and atomic weight. In this item, we have the equation,

     A = (0.412)(21.016 amu) + (0.5012)(21.942 amu) + (0.0868)(23.974 amu)

Simplifying the operation will give us the answer of 21.74 amu.

<em>Answer: 21.74 amu</em>
4 0
3 years ago
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