Laʻana o nā nīnau kūkākūkā Radioactivity
He hanana kūlohelohe ka Radioactivity kahi e palaho koke ai kekahi mau nuclei atomika, e hoʻokuʻu ana i nā ʻāpana a i ʻole ka ikehu ma ke ʻano o ka radiation. Hoʻoulu kēia hanana i nā ʻano hopena like ʻole i ka ʻepekema, ʻenehana, a me ke olakino. He ʻano like ʻole nā hana Radioactivity, akā pono nō hoʻi ka ʻike hohonu e hoʻohana palekana a me ka pono. Ma kēia ʻatikala, e kūkākūkā mākou i kekahi mau pilikia hoʻohālike e pili ana i ka radioactivity a me kā lākou mau hoʻonā, hiki ke kōkua iā ʻoe e hoʻomaopopo hohonu i kēia manaʻo.
Nīnau 1: Ke helu ʻana i ka hapalua ola
Nīnau: Aia i loko o kahi hāpana radioactive he 80 grams o kahi isotope me ka hapalua ola o 10 mau makahiki. ʻEhia ka nui o ka isotope i koe ma hope o 30 mau makahiki?
Kūkākūkā: ʻO ka hapalua ola ka manawa e pono ai no ka hapalua o ka nui mua o kahi isotope radioactive e pala. No ka hoʻoholo ʻana i ka nui o ka isotope i koe ma hope o kekahi manawa, hiki iā mākou ke hoʻohana i ke ʻano palaho:
\[ N = N_0 \left(\frac{1}{2}\right)^{\frac{t}{t_{1/2}}} \]
Ma hea:
– ʻO \( N \) ka helu o nā isotopes i koe.
– ʻO \( N_0 \) ka helu mua o nā isotopes (80 grams).
– ʻO \( t \) ka manawa i hala (30 mau makahiki).
– ʻO \( t_{1/2} \) ka hapalua ola (10 mau makahiki).
Ke hoʻololi nei i nā loli me nā helu i ʻike ʻia:
\[ N = 80 \left(\frac{1}{2}\right)^{\frac{30}{10}} = 80 \left(\frac{1}{2}\right)^3 = 80 \times \frac{1}{8} = 10 \text{ grams} \]
No laila, ma hope o 30 mau makahiki, koe he 10 grams o ka isotope.
Nīnau 2: Ke Hoʻoholo nei i ka Hana Radioactive
Nīnau: Inā ʻo ka hana mua o kahi hāpana radioactive he 2000 Bq a ma hope o 5 mau makahiki e lilo kāna hana i 250 Bq, e hoʻoholo i kona hapalua ola.
Kūkākūkā: ʻO ka hana (\(A\)) o kahi hāpana radioactive e pili pono ana i ka nui o ka isotope i loaʻa:
\[ A = A_0 \left(\frac{1}{2}\right)^{\frac{t}{t_{1/2}}} \]
Ke hoʻohana nei i ka ʻike i hāʻawi ʻia:
– Hana mua (\(A_0\)) = 2000 Bq
– Hana o kēia manawa (\(A\)) = 250 Bq
– Ka manawa i hala (\(t\)) = 5 mau makahiki
E hoʻololi i nā helu i loko o ke ʻano:
\[ 250 = 2000 \left(\frac{1}{2}\right)^{\frac{5}{t_{1/2}}} \]
\[ \frac{1}{8} = \left(\frac{1}{2}\right)^{\frac{5}{t_{1/2}}} \]
No ka hoʻoponopono ʻana i kēia kaulike, hoʻoholo mākou i ka mana o \(\frac{1}{2}\) ka mea e hopena ai i \(\frac{1}{8}\). No laila, \(\left(\frac{1}{2}\right)^3 = \frac{1}{8}\).
No laila, hiki iā mākou ke kākau:
\[ \frac{5}{t_{1/2}} = 3 \]
\[ t_{1/2} = \frac{5}{3} \approx 1.67 \text{ makahiki} \]
No laila, ʻo ka hapalua ola o ka isotope ma kahi o 1.67 mau makahiki.
Nīnau 3: Ikehu Palaho Radioactive
Nīnau: Hoʻopōʻino kahi nucleus atomika ma ka hoʻokuʻu ʻana i kahi ʻāpana alpha (helion: He) a hoʻokuʻu i 5 MeV o ka ikehu. E helu i ka ikehu i hoʻokuʻu ʻia inā e pohō loa ana he 10 grams o ka nucleus. Manaʻo ʻia aia i loko o hoʻokahi mole o kēia nucleus nā ʻātoma mau o Avogadro \(6.022 \times 10^{23}\).
Kūkākūkā: ʻO ka mea mua, pono mākou e hoʻoholo i ka nui o nā ʻātoma i loko o 10 grams. Inā hoʻokuʻu kekahi ʻātoma i 5 MeV, pono mākou e hoʻololi i kēia i ka ikehu holoʻokoʻa no nā ʻātoma āpau.
1. E helu i ka helu o nā mole o ka nucleus:
– Manaʻo ʻia he 210 ke kaumaha ʻātoma o ka nucleus (he laʻana o kahi isotope).
– No laila, ʻo ka helu o nā mole i loko o 10 grams = \(\frac{10}{210}\) moles.
2. E helu i ka helu o nā ʻātoma:
– Helu o nā ʻātoma = \(\frac{10}{210} \times 6.022 \times 10^{23}\).
3. E helu i ka ikehu holoʻokoʻa:
– Ka ikehu holoʻokoʻa = Ka helu o nā ʻātoma 5 MeV.
– E hoʻomanaʻo e hoʻololi iā MeV i joules inā pono (1 MeV = \(1.602 \times 10^{-13}\) J).
No laila:
Helu o nā ʻātoma = \(\frac{10}{210} \times 6.022 \times 10^{23}\).
Ka ikehu holoʻokoʻa = \(\left(\frac{10}{210} \times 6.022 \times 10^{23}\right) \times 5 \times 1.602 \times 10^{-13}\) J.
E hāʻawi kēia i ka nui o ka ikehu i helu ʻia ma Joules.
Ka hopena
Hāʻawi ke kūkākūkā ma luna nei i kekahi mau hiʻohiʻona maʻamau o nā pilikia radioactivity e kū mai paha i nā haʻawina physics nukelea. He mea nui ka hoʻomaopopo piha ʻana i nā manaʻo o ka palaho radioactive, nā helu hapalua ola, a me ka hana a me ka ikehu i hana ʻia e ka palaho, no ka mea, he hopena koʻikoʻi kēia mau mea i nā ʻano ʻoihana like ʻole, me ka lāʻau lapaʻau (ʻoi aku ka radiotherapy), ka ikehu nukelea, a me ka pale ʻana i ka radiation.
ʻO ka hoʻomaopopo ʻana i kēia mau manaʻo kumu ke kumu no ka ʻimi ʻana i nā ʻenehana e hiki mai ana e pili ana i ka radioactivity, a me ka hoʻomaopopo ʻana i ke koʻikoʻi o ka lawelawe palekana ʻana i nā mea radioactive e pale i ke olakino kanaka a me ke kaiapuni. Ma ke ʻano he haumāna a mea noiʻi paha, hiki i ka hiki ke hoʻoponopono i nā pilikia e like me kēia ke kōkua i nā noi ʻepekema hou aʻe a me nā ʻike hou.
