Can I get some help?

Neon has 2 isotopes. Neon-20 has a mass of 19:992 amu and

Alenkinab [10]

Answer:

20.0928.

Explanation:

The average atomic mass is (90 * 19.992 + 10* 21) / 100

= 20.0928.

6 0

3 years ago

Olivia bought new gym shoes to play volleyball because she kept slipping when she ran in her old shoes. How will the new soles h

HACTEHA [7]

Maybe her old shoes had soft worn out bottoms and she slips in them. So her new shoes had more grip than her old ones so they kept her from falling.

6 0

3 years ago

Read 2 more answers

4. Explain what you’ve learned about significant figures. How many significant figures are in the measurement 0.03050 kg?

nasty-shy [4]

There are 4 significant figures! Start counting after the first non-zero digit :)

Hope this helps.

3 0

3 years ago

The rock in a lead ore deposit contains 89 % PbS by mass. How many kilograms of the rock must be processed to obtain 1.5 kg of P

Zolol [24]

Answer:

Approximately 1.9 kilograms of this rock.

Explanation:

Relative atomic mass data from a modern periodic table:

Pb: 207.2;
S: 32.06.

To answer this question, start by finding the mass of Pb in each kilogram of this rock.

89% of the rock is $\rm PbS$ . There will be 890 grams of $\rm PbS$ in one kilogram of this rock.

Formula mass of $\rm PbS$ :

$M(\mathrm{PbS}) = 207.2 + 32.06 = 239.26\; g\cdot mol^{-1}$ .

How many moles of $\rm PbS$ formula units in that 890 grams of $\rm PbS$ ?

$\displaystyle n = \frac{m}{M} = \rm \frac{890}{239.26} = 3.71980\; mol$ .

There's one mole of $\rm Pb$ in each mole of $\rm PbS$ . There are thus $\rm 3.71980\; mol$ of $\rm Pb$ in one kilogram of this rock.

What will be the mass of that $\rm 3.71980\; mol$ of $\rm Pb$ ?

$m(\mathrm{Pb}) = n(\mathrm{Pb}) \cdot M(\mathrm{Pb}) = \rm 3.71980 \times 207.2 = 770.743\; g = 0.770743\; kg$ .

In other words, the $\rm PbS$ in 1 kilogram of this rock contains $\rm 0.770743\; kg$ of lead $\rm Pb$ .

How many kilograms of the rock will contain enough $\rm PbS$ to provide 1.5 kilogram of $\rm Pb$ ?

$\displaystyle \frac{1.5}{0.770743} \approx \rm 1.9\; kg$ .

5 0

4 years ago

A graduated cylinder is filled with 34.4 mL of water. A toy Car that weighs 43.672-g is Gently placed in the cylinder and the wa

Thepotemich [5.8K]

Answer:9.49g/mL

Explanation:

Mass of toy = 43.672g

Volume of water = 34.4mL

Volume of toy + volume of water = 39mL

Volume of toy = 39 — 34.4 = 4.6mL

Density = Mass /volume

Density = 43.672/4.6 = 9.49g/mL

8 0

3 years ago