Answer:

Explanation:
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In this case, since these problems about gas mixtures are based off Dalton's law in terms of mole fraction, partial pressure and total pressure, we can write the following for hydrogen, we are given its partial pressure:

And can be solved for the total pressure as follows:

However, we first calculate the mole fraction of hydrogen by subtracting that of nitrogen to 1 due to:

Then, we can plug in to obtain the total pressure:

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Units to measure pressure are as follows
atm - atmospheric pressure units
kPa - kilo Pascals
mm Hg - milimeters Hg
conversion units are;
1 atm = 101 325 Pa
therefore 4.30 atm = 101 325 Pa / atm x 4.30 atm = 435.7 Pa
1 atm = 760.0 mm Hg
4.30 atm = 760.0 mm Hg / atm x 4.30 atm = 3268 mm Hg
answers are 435.7 Pa and 3268 mm Hg
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The correct option is STRONTIUM.
Strontium is a group 2 element, that means it has two electrons in its outermost shell. This element will prefer to lose these two electrons in its outermost shell in order to attain the octet form, therefore, it will form electrovalent bond with non metals which it can donate two electrons to.