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3 years ago

The following atoms are all variations of the element carbon: 12C, 13C, and 14C due to differing

1 answer:

5 0

Isotopes.
<span>Some isotopes of elements that are not usually radioactive are radioactive because they don't have a suitable number of neutrons. For example carbon-12 is stable but carbon-14 is radioactive. Carbon-12 is much more common.</span>

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Do all forms of radioactive decay change the identity of the original element?

hoa [83]

Explanation:

<h3>yes, Radioactive decay involves the emission of a particle and/or energy as one atom changes into another. In most instances, the atom changes its identity to become a new element.</h3>

5 0

1 year ago

Calculate the molecular weight of a substance. In which the solution of this substance in the water has a concentration of 7 per

Eduardwww [97]

Answer : The molecular weight of a substance is 157.3 g/mol

Explanation :

As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.

Mass of solute = 7 g

Mass of solution = 100 g

Mass of solvent = 100 - 7 = 93 g

Formula used :

$\Delta T_f=i\times K_f\times m\\\\T_f^o-T_f=k_f\times\frac{\text{Mass of substance(solute)}\times 1000}{\text{Molar mass of substance(solute)}\times \text{Mass of water(solvent)}}$

where,

$\Delta T_f$ = change in freezing point

$T_f^o$ = temperature of pure water = $0^oC$

$T_f$ = temperature of solution = $-0.89^oC$

$K_f$ = freezing point constant of water = $1.86^oC/m$

m = molality

Now put all the given values in this formula, we get

$(0-(-0.89))^oC=1.86^oC/m\times \frac{7g\times 1000}{\text{Molar mass of substance(solute)}\times 93g}$

$\text{Molar mass of substance(solute)}=157.3g/mol$

Therefore, the molecular weight of a substance is 157.3 g/mol

7 0

3 years ago

Pls help asap!!!!

AVprozaik [17]

Answer: The pressure of the He is 2.97 atm

Explanation:

According to Dalton's law, the total pressure is the sum of individual pressures.

$p_{total}=p_{N_2}+p_{O_2}+p_{He}.$

Given : $p_{total}$ =total pressure of gases = 6.50 atm

$p_{N_2}$ = partial pressure of Nitrogen = 1.23 atm

$p_{O_2}$ = partial pressure of oxygen = 2.3 atm

$p_{He}$ = partial pressure of Helium = ?

putting in the values we get:

$6.50atm=1.23atm+2.3atm+p_{He}$

$p_{He}=2.97atm$

The pressure of the He is 2.97 atm

3 0

2 years ago

An element's atomic mass does not include the mass of its <br> Electrons <br> Protons <br> Neutrons

klio [65]

Mass of electrons are not included when calculating the atomic mass of element. Atomic mass of the element is equal to proton + neurons. Example the the mass number of Nitrogen can be calculated as 7 protons + 7 neutrons to give 14 . thus nitrogen has a mass number of 14

4 0

3 years ago

If 97.3 L of NO2 forms measured at 35 C and 632 mm Hg. What is the percent yield?

enyata [817]

<span>a. Use PV = nRT and solve for n = number of mols O2.
mols NO = grams/molar mass = ?

Using the coefficients in the balanced equation, convert mols O2 to mols NO2. Do the same for mols NO to mols NO2. It is likely that the two values will not be the same which means one is wrong; the correct value in LR (limiting reagent) problems is ALWAYS the smaller value and the reagent producing that value is the LR.

b.
Using the smaller value for mols NO2 from part a, substitute for n in PV = nRT, use the conditions listed in part b, and solve for V in liters. This will give you the theoretical yield (YY)in liters. The actual yield at these same conditions (AY) is 84.8 L.

</span>and % will be 60%.

3 0

2 years ago