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lesantik [10]
3 years ago
9

Index Fossils

Chemistry
1 answer:
Hitman42 [59]3 years ago
8 0
Im not sure what the choices are but index fossils can help with the geological time scale and they are traces of animals left behind that became fossilized. Hope this helps シ
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A sample of thorium-234 has a half life of 25 days. Will the thorium undergo rafioacrive decay and be completely gone in 100 day
Sunny_sXe [5.5K]
I don't know terribly much about radioactive decay, but yes, it WILL decay. If it's half life is 25 days, it will be completely consumed in 50 days. By 100 days, it should be long gone. As far as I know, the reason for this is (besides the simple math which is self-explanatory) the Thorium has so many protons/neutrons, it's unstable and thus undergoes radioactive decay as it cannot maintain stable form.

I hope this helps! :) 
6 0
4 years ago
What's the equation for the reaction of Trifluoro bromide with Ammonia gas. ( brainliest assured )​
sp2606 [1]

Answer:

Ammonium bromide can be prepared by the direct action of hydrogen bromide on ammonia. It can also be prepared by the reaction of ammonia with iron(II) bromide or iron(III) bromide, which may be obtained by passing aqueous bromine solution over iron filings.

Explanation:

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5 0
3 years ago
Equal volumes of two solutions, one containing a strong acid at pH 2 and the other containing a strong base at pH 12, are mixed.
mash [69]

Answer:

7  

Explanation:

Assume we have 1 L of each solution.

Solution 1

\text{[H$^{+}$]}= 10^\text{-pH} \text{ mol/L} = 10^{\text{-2}} \text{ mol/L}\\ \text{ moles of H}^{+} = \text{ 1 L solution} \times \dfrac{10^{-2}\text{ mol H}^{+}}{\text{1 L solution}} = 10^{-2}\text{ mol H}^{+}

Solution 2

pH = 12

pOH = 14.00 - pOH = 14.00 - 12 = 2.0

\text{[OH$^{-}$]}= 10^\text{-pOH} \text{ mol/L} = 10^{\text{-2}} \text{ mol/L}\\ \text{ moles of OH}^{-} = \text{ 1 L solution} \times \dfrac{10^{-2}\text{ mol OH}^{-}}{\text{1 L solution}} = 10^{-2}\text{ mol OH}^{-}

3. pH after mixing

               H⁺  +  OH⁻ ⟶ H₂O

I/mol:     10⁻²    10⁻²  

C/mol:   -10⁻²   -10⁻²

E/mol:      0        0

The H⁺ and OH⁻ have neutralized each other. The pH will be that of pure water.

pH = 7

8 0
4 years ago
What is meant by reactive elements​
Vlad1618 [11]

Answer; relative elements are most reactive elements and compounds may ignite spontaneously or explosively. They generally burn in water as well as the oxygen in the air

Explanation:

6 0
3 years ago
Which number represents a basic pH, 4 or 9
jekas [21]
I know 4 is acidic so it has to be 9
8 0
4 years ago
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