Helium - 4 isotope has 2 protons and 2 neutrons.
Its atomic number is 2 (the number of protons). Atomic number is the number of protons in the atom of an element and it identifies the element. All the isotopes of an element have the same atomic number (same number of protons). So, all the isotopes of hellium have 2 protons.
The number 4 that identifies the helium - 4 isotope is the mass number, i.e. the number of protons plus the number of neutron. So, helium-4 isotope has 2 protons and 2 neutrons. While, other isotopes of helium have 2 protons but different number of neutrons.
The atomic number enable us to deduce the number of electrons in an atom because the atoms are neutral, which implies that the positive and negative charge are equal. Given that the magnitude of the charge of electons and protons are equal but the sign is opposed (protons are positve and electrons are negative) the number of electrons in the atom equals the number of protonts. That is why the atomic number is also the number of electrons of the atom.
The answer is genotype because those are the letters .
Hess law can help us to obtain the enthalpy of a series of reactions by summation. The missing enthalpy of this reaction is −198kJ.
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What is Hess law?</h3>
According to the Hess law of constant heat summation, the enthalpy of a sequence of reactions can be obtained as the sum of the enthalpies of all the reactions.
Now looking at all the reavtion written here in order to obtain the missing enthalpy, we conclude that the missing enthalpy is −198kJ.
Learn more about enthalpy: brainly.com/question/3393755
The answer would be 5.5g because you have to subtract 8.2 minus 2.7 and you get 5.5g so basically the answer is C.
One mole of a substance is defined by Avogadro as consisting of 6.022 x 1023 atoms. This is Avogadro's number. To calculate the number of atoms in two moles of sodium, use dimensional analysis. 2.0 moles Na x 6.022⋅1023g1mol=1.20⋅1024 atoms of Na
