Match each group on the periodic table with its description. HELP ME PLS

How many atoms of gold are in a pure gold coin weighing 12.0g?

grigory [225]

12.0g x 1 mol / 63.546g = 0.188839581mol

So, for every 1 mole, we have 6.022 x 10^23 of whatever we're measuring. This gives us a conversion factor of (1 mole / 6.022 x 10^23 atoms) or (6.022 x 10^23 atoms / 1 mole).

0.188839581 mol x (6.022 x 10^23 atoms) / 1 mol = 1.137191955 x 10^23

Remember from before that we are limited to 3 significant figures. Since our calculations are complete, we can now round down to: 1.14 x 10^23 

That should be your answer!

Hope it helps!
xo

3 0

3 years ago

The Average Speed of the orbiting space shuttle is

maxonik [38]

Explanation:

It is given that, the Average Speed of the orbiting space shuttle is 17500 miles/hour.

We need to convert the speed in kilometers/ second

We know that,

1 mile = 1.609 km

or

1 km = 0.621 miles

1 hour = 3600 seconds

$17500\ \dfrac{\text{miles}}{\text{hour}}=17500\ \dfrac{\text{miles}}{\text{h}}\times \dfrac{1\ h}{3600\ s}\\\\=17500\times \dfrac{\text{miles}}{3600\ s}$

Now cancel the miles in numerator.

$17500\times \dfrac{\text{miles}}{3600\ s}=17500\times \dfrac{\text{miles}}{3600\ s}\times \dfrac{1.609\ km}{1\ \text{miles}}\\\\=17500\times \dfrac{1.609}{3600}\ km/s\\\\=7.82\ km/s$

So, 17500 miles/hour is equal to 7.82 km/s.

8 0

3 years ago

How is an oscilloscope used to tune a musical instrument?

sp2606 [1]

It uses the voltages and sound freq. in the air to measure the wave lengthths

4 0

3 years ago

You have added IgG-sensitized red cells to the negative indirect antiglobulin test result of the antibody screen procedure. You

Ivanshal [37]

Answer:

Positive

Explanation:

The antibody screen interpretation is positive. That's because of clump formation when antibody reacts with the antigen and agglutination occurs.

It means that the antibodies were present in the sample that react with the antigen present in the test tube.

5 0

3 years ago

A certain substance, X, has a triple-point temperature of 20°C at a pressure of 2.0 atm.

nikitadnepr [17]

Answer: The statement which could possibly not be true is C -" Liquid X can exist as a stable phase at 25°C, 1atm."

Explanation:

Triple point is the point where a substance co-exist as solid liquid and gas. At any point other than the triple point, the substance exist as a single phase substance.

As shown in the diagram, Liquid cannot exist as a stable phase at 1atm( below the the triple point pressure of 2atm) as the liquid can only exist beyond the pressure of triple point.

3 0

3 years ago