Answer:
Iron 55 (Fe-55) is the iron isotope whose nucleus consists of 26 protons and 29 neutrons. It is a radioisotope that disintegrates by electron capture in manganese 55.
Explanation:
i hope this helps if not tell me
none of the above is the answer i think?!
Answer:
Fossil fuels contribute to greenhouse gases, which is one of their major disadvantages. The most harmful for the environment is coal because it has many more harmful combustion products than other fossil fuels.
Answer:
True
Explanation:
Because atoms with the same number of valence electrons react in similar ways with other elements.
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.
