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3 years ago

The atomic number of magnesium is 12 this is also the number of which of the following

Chemistry

1 answer:

frozen [14]3 years ago

4 0

The atomic number represents the number of protons present in an atom.Therefore,the answer is B.

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Someone help me please.. I will mark as brainliest I promise...

Kobotan [32]

Answer:

(a) proton

(b) neutron

particles in nucleus are proton and neutron.

atom is electrically neutral because no.of proton= no.of electron=6

5 0

2 years ago

Are specimens the best source of DNA

xxTIMURxx [149]

no the best source is blood.

5 0

3 years ago

Oo help it’s for a grade

EastWind [94]

Answer: D.kinectic energy

Explanation

8 0

2 years ago

What is the boiling point of a solution produced by adding 610 g of cane sugar (molar mass 342.3 g/mol) to 1.4 kg of water? For

wel

Answer:

Boiling point of solution is $100.65^{0}\textrm{C}$

Explanation:

Cane sugar is a non-volatile solute.

According to Raoult's law for a non-volatile solute dissolved in a solution-

$\Delta T_{b}=K_{b}.m$

Where, $\Delta T_{b}$ is elivation in boiling point of solution, $K_{b}$ is ebbulioscopic constant of solvent (how much temperature is raised for dissolution of 1 mol of non-volatile solute) and m is molality of solution.

Here, $K_{b}=0.51^{0}\textrm{C}.kg.mol^{-1}$

610 g of cane sugar = $\frac{610}{342.3}$ moles of cane sugar

= 1.78 moles of cane sugar

So, molality of solution (m) = $\frac{1.78}{1.4}mol.kg^{-1}=1.27mol.kg^{-1}$

Plug in all the values in the above equation, we get-

$\Delta T_{b}=0.51^{0}\textrm{C}.kg.mol^{-1}\times 1.27mol.kg^{-1}=0.65^{0}\textrm{C}$

So, boiling point of solution = $(100+0.65)^{0}\textrm{C}=100.65^{0}\textrm{C}$

7 0

3 years ago

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs

Akimi4 [234]

Answer and Explanation:

At constant pressure and constant temperature, the Gibbs free energy of a process is given by the following equation:

ΔG= ΔH - T ΔS

The process is spontaneous when ΔG<0. For this, there are four alternatives depending on the signs of ΔH and ΔS and the temperature (T):

1) ΔH negative, ΔS positive ⇒ b)The reaction will be spontaneous at all temperatures.

ΔG= (-H) - T (+S) ⇒ ΔG<0 always

2) ΔH positive, ΔS negative ⇒ c)The reaction will be nonspontaneous at all temperatures.

ΔG= (+H) - T (-S) ⇒ ΔG>0 always

3) ΔH negative, ΔS negative ⇒ d)The reaction will be spontaneous at low temperature, but nonspontaneous at high temperature.

ΔG= (-H) - T (-S) ⇒ ΔG<0 if TΔS is lower than ΔH, because is the positive term

4)ΔH positive, ΔS positive ⇒ a)The reaction will be nonspontaneous at low temperature, but spontaneous at high temperature.

ΔG= (+H) - T (+S) ⇒ ΔG<0 if TΔS higher than ΔH because is the negative term

8 0

3 years ago