Answer:
Nobelium is made by the bombardment of curium (Cm) with carbon nuclei. Its most stable isotope, 259No, has a half-life of 58 minutes and decays to Fermium (255Fm) through alpha decay or to Mendelevium (259Md) through electron capture.
Explanation:
The total number of valence electrons is 20.(1 from hydrogen, 5 from nitrogen, and 7 from each fluorine so 14 for both) connect all the atoms with a single bond( each bond counts as 2) so far there is 6 electrons so you need to fill in the rest of the 14 and you get the result in the picture.
The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it. Aluminium oxide has a very high melting point (over 2000°C) so it would be expensive to melt it. The use of cryolite reduces some of the energy costs involved in extracting aluminium.
Electron cloud is the region around the nucleus in an atom where we can locate an electron.
The concept of electron cloud model was introduced by the Schrodinger and Heisenberg. According to this model, it would be difficult to know the position of the electrons in an atom and they are not particles that orbit around the nucleus. We can only expect the electrons to be present in specific areas called the electron clouds around the nucleus. It is the quantum mechanical model that used the concept of electron clouds. According to the model, the electron cloud or an orbital is a space around the nucleus in an atom where the probability of finding an electron is 90%. It explains that electrons show wave nature. It is difficult to determine the exact position and momentum of an electron in an atom.
Answer:
45.7kj
Explanation:
To calculates the heats of reaction from heats of formation:
∆Hr=£∆Hp -£∆Hr
= £∆Hch3ChOH - £∆HCh2h2+h20
=(-235.1kj)-(+52.47kj/kg + (-241.8kj/kg)
∆H = 45.71kj/kg
