which statement accurately describes the atoms of a specific element?
a) an indium‚ in‚ atom contains 115 protons inside the nucleus and 49 neutrons outside the nucleus.
b) a scandium‚ sc‚ atom contains 45 electrons outside the nucleus and 21 neutrons inside the nucleus.
c) an aluminum‚ al‚ atom contains 27 electrons and 27 protons inside the nucleus.
d) a zinc‚ zn‚ atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus.

The statement that accurately describes the given element is;

D) A zinc‚ Zn‚ atom contains 30 protons inside the nucleus and 30 electrons outside the nucleus.

This is about knowing atomic number, mass number and their definitions.

By definition, Atomic number is the number of electrons or number of protons present in an atom that is neutral.

Thus;

Atomic number = Number of electrons = Number of protons

Meanwhile, by definition, mass number is the sum of number of protons and neutrons present in a neutral atom.

Thus;

Mass number = Number of protons + Number of neutrons

Let's look at the options;

On the periodic table, the element Indium is the 49th element. It has a mass number of 115 and atomic number of 49.

From earlier, we saw that;

Atomic number = Number of electrons = Number of protons

Thus;

Number of protons = Number of electrons = 49

Also, we saw that;

Mass number = Number of protons + Number of neutrons

Thus;

115 = 49 + number of neutrons

Number of neutrons = 115 - 49

Number of neutrons = 66

Number of neutrons gotten here is not same with the option.

Thus,option A is incorrect.

Thus;

Number of protons = Number of electrons = 21

Number of neutrons = 45 - 21

Number of neutrons = 24

Number of neutrons here differs from that given and so this option is incorrect.

Thus;

Number of protons = Number of electrons = 13

This is different from the 27 in the option. Thus, this option is incorrect.

Thus;

Number of protons = Number of electrons = 30

Thus corresponds with what is given in the option since electrons are outside the nucleus while protons are inside.

Thus, option D is correct.

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answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol