Methane burns, and carbon dioxide and water appear: new substances, same elements. A uranium nucleus splits, and barium and krypton appear: the uranium atoms themselves are gone. The second change reaches somewhere the first never touches.
From earlier science you know the atom's parts: protons and neutrons sit in the nucleus, and electrons sit around it. You also know that the number of protons fixes which element an atom is. This lesson uses both facts to tell two kinds of change apart.
A nuclear change rearranges the protons and neutrons of the nucleus itself.
Because the proton count can change, a nuclear change can turn an atom into a different element.
A chemical change only rearranges how atoms bond to one another, and it leaves every nucleus untouched.
Uranium splitting into barium and krypton is a nuclear change: the nuclei themselves were rearranged, and the element changed.
Methane burning to carbon dioxide and water is a chemical change: every carbon, hydrogen and oxygen nucleus came through untouched.
One question sorts any change: did the nuclei themselves change?
If the nuclei changed, the change is nuclear; if only the bonding changed, the change is chemical.
A uranium nucleus splits into a barium nucleus and a krypton nucleus. Is the change nuclear or chemical?
The sorting question is whether the nuclei themselves changed.
A uranium nucleus became a barium nucleus and a krypton nucleus, so the nuclei themselves were rearranged.
A change that rearranges the nucleus itself is a nuclear change.
The change is nuclear, and the element changed with it.
Methane burns in oxygen, making carbon dioxide and water. Is the change nuclear or chemical?
The sorting question is whether the nuclei themselves changed.
The carbon, hydrogen and oxygen atoms bonded into new groupings, but every nucleus came through untouched.
A change that only rearranges bonds is a chemical change.
The change is chemical, and every atom is still its original element.
What does a nuclear change rearrange?
A sodium nucleus absorbs a stray neutron. Is the change nuclear or chemical?
Mireille says: 'Only a nuclear change can turn an atom of one element into an atom of a different element.' Is Mireille correct?
Methane burns in oxygen, making carbon dioxide and water. What happens to the nuclei of the atoms involved?
Which of these is a nuclear change?
What do we call a change that rearranges the protons and neutrons of the nucleus itself?