Ranya has watched the heaviest nuclei split. Now for the lightest nuclei there are. When two of them collide and merge, something new is made, and a large amount of energy is released.
You have seen fission: a heavy nucleus splits into two smaller nuclei. This lesson is the opposite change, and it belongs to the lightest nuclei. You will also need the element-number names from the isotope lesson: a name like uranium-235 gives the nucleus's total count of protons plus neutrons.
Two light nuclei can collide and merge into a single heavier nucleus.
The merge releases a large amount of energy.
Hydrogen has isotopes, and two of them carry their own names.
Hydrogen-2, one proton and one neutron, is called deuterium.
Hydrogen-3, one proton and two neutrons, is called tritium.
A deuterium nucleus and a tritium nucleus can merge into a helium nucleus plus a free neutron.
Count the protons and neutrons: 2 + 3 = 5 go in, and 4 + 1 = 5 come out. Every proton and neutron that went in is still there.
Fusion is a nuclear change: the protons are rearranged into one nucleus, and a new element, helium, is made.
Where does fusion's released energy come from? The next lesson answers that for fission and fusion at once.
A deuterium nucleus (one proton, one neutron) merges with a tritium nucleus (one proton, two neutrons). The products are a helium nucleus and one free neutron. Do the proton and neutron counts balance?
Count the protons in: 1 + 1 = 2. The helium nucleus holds both, so 2 protons come out.
Count the neutrons in: 1 + 2 = 3. The helium nucleus holds 2 of them, and 1 leaves free, so 3 come out.
Totals: 5 particles in, 5 particles out.
Yes. Every proton and neutron that went in is still there in the products.
Two light nuclei merge into one heavier nucleus. Is this change nuclear or chemical?
A chemical change only rearranges how atoms bond and leaves every nucleus untouched.
Merging two nuclei rearranges the protons and neutrons of the nuclei themselves.
A change that rearranges the nucleus is nuclear.
The merge is a nuclear change.
During nuclear fusion, what happens to the two light nuclei?
A hydrogen nucleus holds one proton and one neutron. Which name does this nucleus carry?
Nikau says: 'In the deuterium plus tritium fusion, every proton and neutron that went in is still there in the products.' Is Nikau correct?
Which statement describes nuclear fusion?
Two deuterium nuclei, each holding 2 protons and neutrons in total, merge into a single nucleus plus one free neutron. How many protons and neutrons does the merged nucleus hold?
Two light nuclei merge into one heavier nucleus, releasing energy. What is this nuclear change called?