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3 years ago

Which unstable element is used to determine the age of volcanic rock?

Chemistry

2 answers:

Len [333]3 years ago

8 0

Answer:

Potassium

Explanation:

Just took test on Ed2020

77julia77 [94]3 years ago

6 0

Answer:

Potassium.

Explanation:

Therefore, the answer is Potassium. You might think, that because we were talking about Argon as well, the answer is both of them, but no. Everything starts with Potassium but it decays into Argon during the process.

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Arrhenius base definition

kompoz [17]

Arrhenius base is a substance that , when dissolved in an aqueous solution , increase the concentration of hydroxide (OH) ion in the solution

I hope that's help !

6 0

3 years ago

Round off each number to the indicated number significant figures (sf):

qaws [65]

Answer :

(a) The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number in 3 significant figures will be, $2.24\times 10^1$

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

(a) The given number 00003554 converted into 2 significant figures.

In 00003554, there are 4 significant figures. Now we have to convert it into 2 significant figures.

The given number in 2 significant figures will be, $3.6\times 10^3$

(b) The given number 35.8348 converted into 4 significant figures.

In 35.8348, there are 6 significant figures. Now we have to convert it into 4 significant figures.

The given number in 4 significant figures will be, $3.583\times 10^1$

(c) The given number 22.4555 converted into 3 significant figures.

In 22.4555, there are 6 significant figures. Now we have to convert it into 3 significant figures.

The given number in 3 significant figures will be, $2.24\times 10^1$

7 0

3 years ago

Tris is a molecule that can be used to prepare buffers for biochemical experiments. It exists in two forms: Tris (a base) and Tr

ale4655 [162]

Solution :

For the reaction :

$\text{TrisH}^+ + H_2O \rightarrow \text{Trish}^- + H_3O^+$

we have

$Ka = \frac{[\text{Tris}^- \times H_3O]}{\text{Tris}^+}$

$=\frac{x^2}{0.02 -x}$

$=8.32 \times 10^{-9}$

Clearing $x$ , we have $x = 1.29 \times 10^{-5} \text{ moles of acid}$

So to reach $\text{pH} = 7.8 (\text{pOH}= 14-7.8=6.2)$ , one must have the $\text{OH}^-$ concentration of the :

$\text{[OH}^-]=10^{-pOH} = 6.31 \times 10^{-7} \text{ moles of base}$

So we can add enough of 1 M NaOH in order to neutralize the acid that is calculated above and also adding the calculated base.

$\text {n NaOH}=1.29 \times 10^{-5}+6.31 \times 10^{-7}$

$= 1.35 \times 10^{-5} \text{ moles}$

Volume NaOH $= 1.35 \times 10^{-5} \text{ moles} \times \frac{1000 \text{ mL}}{1 \text{ mol}} = 0.0135 \text{ mL}$

Tris mass $H^+ = 0.02 \text{ mol} \times 157.6 \text{ g/mol}=3.152 \text{ g}$

Now to prepare the said solution we must mix:

$3.152 \text{ g Tris H} + 0.0135 \text{ mL NaOH} \ 1 M$ gauge to 1000 mL with water.

3 0

3 years ago

List three common counting units and their values.

emmasim [6.3K]

Dozen = 12,

ii. 1 score = 20

iii. 1 ream = 500

iv. 1 gross = 1.44

6 0

3 years ago

What really is the Ebola virus?

Sloan [31]

The Ebola virus belongs to a family of viruses termed Filoviridae. Filovirus particles form long sometimes branched filaments of varying shapes, as well as shorter filaments , and may measure up to 14,000 nanometers in length with diameter of 80 nanometers. Viral particles contain one molecule of single stranded RNA enveloped in a lipid membrane. New viral particle bud from the surface of their host cell. Although Ebola virus was only discovered in 1976, it is an ancient virus and is thought to have split from other viruses thousands of years ago.

7 0

3 years ago