All categories

3 years ago

E. Give evidence to support or dispute: "In nature, the chance of finding one isotope

Chemistry

1 answer:

Nadusha1986 [10]3 years ago

3 0

Answer:

This question appears incomplete

Explanation:

However, the chance of finding one isotope of an element is not the same for all elements because some elements/isotopes are more in abundance than some other elements/isotopes; for example the most abundant element on earth is nitrogen-14, hence the chances of finding nitrogen-14 in nature is higher the chances of finding any isotope of Xenon.

Also, while isotopes occur naturally, some do not. Hence, the chances of finding a naturally occurring isotopes (no matter how rare like Xenon-126) is higher than the chances of finding artificial radioisotopes like technetium-95 and promethium-146 (whose chances are zero because they cannot be found naturally occurring).

You might be interested in

In the reaction, Zn(s) + 2 HCl(aq) --> ZnCl2 (aq)+ H2(g), 25 grams of Zn are reacted with 17.5 g of HCl. How many grams of H2

Gennadij [26K]

Answer:

0.480 g of H₂ are produced, in the reaction.

Explanation:

This is the reaction:

Zn(s) + 2HCl → ZnCl₂ (aq) + H₂ (g)

We havethe mass of both reactants, so we must work with them to find out the limiting reactant and then, determine the amount of H₂ produced.

Let's convert the mass to moles ( mass / molar mass)

25 g / 65.41 g/mol = 0.382 moles Zn

17.5 g / 36.45 g/mol = 0.480 moles HCl

Ratio is 1:2, so 1 mol of Zn react with the double of moles of HCl.

0.382 moles of Zn would need the double of moles to react, so (0.382 .2) = 0.764 moles of HCl. → We only have 0.480 moles, so the acid is the limiting.

Now let's determine the moles of H₂ formed.

Ratio is 2:1, so If i take account the moles I have, I will produce the half of moles of my product.

0.480 moles / 2 = 0.240 moles of H₂ are produced.

To find out the mass, we must multiply mol . molar mass

0.240 mol . 2g/mol = 0.480 g

3 0

3 years ago

2. Classify the following solutions as acidic, basic, or neutral at 25OC.

PilotLPTM [1.2K]

Answer: a) pH = 13.00 : basic

b) $[H_3O^+]=1.0\times 10^{-12}$ : basic

c) pOH = 5.00 : basic

d) $[OH^-]=1.0\times 10^{-9}$ : acidic

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

$pH=-\log [H_3O^+]$

Acids have pH ranging from 1 to 6.9 and bases have pH ranging from 7.1 to 14.Neutral substances have pH of 7.

a) pH = 13.00

As pH is more than 7, the solution is basic.

b) $[H_3O^+]=1.0\times 10^{-12}$

Putting in the values:

$pH=-\log[1.0\times 10^{-12}]$

$pH=12$

As pH is more than 7, the solution is basic.

c) pOH = 5.00

$pH+pOH=14.0$

$pH=14.0-5.00=9.00$

As pH is more than 7, the solution is basic.

d) $[OH^-]=1.0\times 10^{-9}$

Putting in the values:

$pOH=-\log[1.0\times 10^{-9}]$

$pOH=9.00$

$pH+pOH=14.0$

$pH=14.0-9.00=5.00$

As pH is less than 7, the solution is acidic.

3 0

3 years ago

a. Calculate the pH of a solution that has [H3O+]= 4.3 x 10-5 M. b. Is the solution acidic or basic? How do you know?

Luda [366]

Answer:

* $pH=4.37$

* The solution is acidic since the pH is below 7.

Explanation:

Hello,

In this case, we can mathematically define the pH by:

$pH=-log([H_3O^+])$

Thus, for the given hydronium concentration we simply compute the pH:

$pH=-log(4.3x10^{-5})=4.37$

Thereby, we conclude the solution is acidic due to the fact that the pH is below 7 which is the neutral point and above it the solutions are basic.

Regards.

3 0

2 years ago

29.47 mL of a solution of the acid HBr is titrated, and 72.90 mL of 0.2500-M NaOH is required to reach the equivalence point. Ca

Klio2033 [76]

The original concentration of the acid solution is 6.175 $\times$ 10^-4 mol / L.

<u>Explanation:</u>

Concentration is the ratio of solute in a solution to either solvent or total solution. It is expressed in terms of mass per unit volume

HBr + NaOH -----> NaBr + H2O

There is a 1:1 equivalence with acid and base.

Moles of NaOH = 72.90 $\times$ 10^-3 $\times$ 0.25

= 0.0182 mol.

[ HBr ] = moles of base / volume of a solution

= 0.0182 / 29.47

= 6.175 $\times$ 10^-4 mol / L.

4 0

3 years ago

Both kepler's laws and newton's laws tell us something about the motion of the planets, but there are fundamental differences be

I am Lyosha [343]

Answer: See description

Explanation:

Kepler's laws have three principal points:

1. planets orbit the sun in elliptical paths

2. the orbial period is related to the orbital distance by $T^{2} = d^3$

where T is the orbital period and d is the orbital distance, T is in years and d is measured in units of the earth sun distance.

3. planets closer to the sun move faster than planets far away from it.

Newton:

Newton discovered that there is a consequence to the gravity exerted by objects: mass, the heavier the planet, the more gravitational force it posseses ( thats why we orbit the sun)

with the gravitational force $F_{gravitational} =G \frac{Mm}{r^2}$ newton discovered the inverse-quadratic relationship between the distance of the planets and the acceleration exerted by the force one could exert on another.

Kepler's laws were mostly based on observed evidence with quantitative relationships between the mentioned variables. Newton's laws are based on calculus and symbolic equations. While Kepler's mode is basic, Newton took another step in and build a more general model for gravity (which was improved by general relativity later). In a nutshell Newton proved the scientific causes for Kepler's laws...

3 0

3 years ago