A) How many moles of gold atoms are present in a 295-gram sample of gold? B) How many gold atoms would there be in the sample?

Answer:

A) entropy

Explanation:

In gamma decay, no change in proton number occurs, so the atom does not become a different element

Answer: Carbon-14 isotope is used to date ancient artifacts such as fossils.

Explanation:

To determine the age of ancient artifacts such as fossils, we use radiocarbon dating process.

In this process, a naturally occurring radioisotope of carbon which is Carbon-14 is used. This isotope is generally used because this isotope gets constantly created in the atmosphere with the interaction of cosmic rays with the nitrogen present in atmosphere.

Hence, an isotope of carbon which is Carbon-14 is used to determine the age of ancient artifacts such as fossils.

Answer:

1.74845

Explanation:

We have the following reaction:

I2 + H2 => 2 HI

Now, the constant Kc, has the following formula:

Kc = [C] ^ c * [D] ^ d / [A] ^ a * [B] ^ b

In this case I2 is A, H2 is B and C is HI

We know that the values are:

 H2 = 1 × 10 ^ -3 at 448 ° C

I2 = 2 × 10 ^ -3 at 448 ° C

HI = 1.87 × 10 ^ -3 at 448 ° C

Replacing:

Kc = [1.87 × 10 ^ -3] ^ 2 / {[2 × 10 ^ -3] ^ 1 * [1 × 10 ^ -3] ^ 1}

Kc = 1.87 ^ 2/2 * 1

Kc = 1.74845

Which means that at 448 ° C, Kc is equal to 1.74845

Answer:

Explanation:

[H2] = 10^-3

[I2] = 2*10^-3

[HI] = 0

in equilbiirum

[H2] = 10^-3 - x

[I2] = 2*10^-3 -x

[HI] = 0 + 2x

and we know

[HI] = 0 + 2x = 1.87*10^-3

x = ( 1.87*10^-3)/2 =  0.000935

then

[H2] = 10^-3 - 0.000935 = 0.000065

[I2] = 2*10^-3 -0.000935 = 0.001065

                        H₂                +          I              ⇄              2 HI

Initially     1 × 10⁻³                       2 × 10⁻³

Change  -9.35 × 10⁻⁴               -9.35 × 10⁻⁴                +1.87 × 10⁻³

At equil   6.5 × 10⁻⁵                  1.06 5 × 10⁻³               1.87 × 10⁻³

HI increase by 1.87 × 10⁻³M