Answer:
The molar mass of carbon
Explanation:
Before the mass (in grams) of two moles of carbon can be determined, <u>the molar mass of the element would be needed.</u>
<em>This is because the number of mole of an element is the ratio of its mass and the molar mass</em>. That is,
number of mole = mass/molar mass
Hence, the mass of elements can be obtained by making it the subject of the formular;
mass = number of mole x molar mass
<em>Therefore, the molar mass of carbon would be needed before the mass of 2 moles of the element can be determined.</em>
Answer: 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4
Explanation:
I suggest looking at the electron configuration chart, it has really helped me a lot :)
Answer is: a. Rubidium (Rb) is more reactive than strontium (Sr) because strontium atoms must lose more electrons.
The ionization energy (Ei) is the minimum amount of energy required to remove the valence electron, when element lose electrons, oxidation number of element grows (oxidation process).
Alkaline metals (group 1), in this example rubidium, have lowest ionizations energy and easy remove valence electrons (one electron), they are most reactive metals.
Earth alkaline metals (group 2), in this example strontium, have higher ionization energy than alkaline metals, because they have two valence electrons, they are less reactive.
Rubidium electron configuration: ₃₇Rb 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s¹; one valence electron is 5s¹ orbital.
Strontium electron configuration: ₃₈Sr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²; two valence electrons is 5s² orbital.
The atomic number is 6, you can also find out by the amount of electrons because, electrons and protons have the same charge.
