Which elements are magnetic in the periodic table?

How to calculate density (what’s the formula) <br> density=_ divided by _

Sphinxa [80]

Answer:

density equals weigt divided by volume

Explanation:

$density = \frac{m}{v}$

8 0

3 years ago

High concentrations of carbon monoxide CO can cause coma and possible death. The time required for a person to reach a COHb leve

prohojiy [21]

Answer:

The exposure time that equals 750 is 3.4 hr

Explanation:

The given formula is:

$[tex]T=.0002*x^{2} -.316*x+127.9$ [/tex]

In the formula:

T= exposure time

x= carbon monoxide present in ppm

So, to calculate the exposure time when carbon monoxide is 750ppm, you should replace the "x" by 750.

$[tex]T=.0002*750^{2} -.316*750+127.9$ [/tex]

T=3.4hr

8 0

3 years ago

Select the correct answer. Thomas has 235 grams of K2S in the chemistry lab. How many atoms of potassium (K) are in 235 grams of

Readme [11.4K]

Atoms are the smallest division of the element. The potassium atoms present in the 235 gm of the compound is $2.57 \times 10^{24}$ atoms.

<h3>What is the number of atoms?</h3>

Given,

Mass (m) of Potassium sulfide $(\rm K_{2}S)$ = 235 gm
Molar mass (M) of Potassium sulfide = 110.26 g/mol

Calculate the number of moles as:

$\begin{aligned}\rm Moles (n) &= \dfrac{\rm mass}{\rm molar\;\rm mass}\\\\&= \dfrac{235}{110.26}\\\\&=2.13\;\rm mol\end{aligned}$

In the given compound $\rm K_{2}S$ , there are two atoms of potassium and one atom of sulphur.

If, 1 mole = $2 \times 6.022 \times 10^{23}$ atoms of potassium

Then, 2.13 moles = X atoms

Solving for X:

$2.13 \times 2 \times 6.022 \times 10^{23} = 2.57 \times 10^{24}$

Therefore, option c. $2.57 \times 10^{24}$ is correct.

Learn more about atoms here:

brainly.com/question/11411852

6 0

3 years ago

If a bar of motilium cost .0.2 dollars how much will 200 bars cost

lorasvet [3.4K]

Answer: 40

Explanation: 0.2 x 200

3 0

3 years ago

Given the balanced equation representing a reaction:

expeople1 [14]

Answer: (3) Energy is absorbed as bonds are broken, and energy is released as bonds are formed.

Explanation:

1) The equation given is H₂(g) + Cl₂(g) → 2HCl(g) + energy

2) The energy is shown in the product side, so energy is a product of the reaction, so energy is release.

But this is just the net energy of the process. You need more insight to deal with the energy changes in the reaction.

3) Chemical bonds store energy; this stored energy is the potential chemical energy of the molecules.

When a chemical reaction occurs, the first stage is to brake bonds.

Braking chemical bonds requires energy to overcome the bond energy. Braking bonds always absorbs energy.

On the other hand, forming bonds always release energy.

The neat energy of the reaction is the difference between the energy needed to break bonds and the energy released when new bonds form.

So, regardless the fact that, in the chemical equation that represents the reaction a net energy release is shown, you know that energy is absorbed as bonds are broken, and energy is released as bonds are formed (option 3).

5 0

3 years ago