half life & radioisotopes

Diagram shows the decay curve of a radioactive substance.

Rajah menunjukkan lengkungan reputan bagi satu bahan radioaktif.

If the initial activity of the radioactive substance is 160 counts per second, what is the activity after 90 days?

Jika keaktifan awal bagi bahan radioaktif itu ialah 160 bilangan per saat, berapakah keaktifannya selepas 90 hari?

• 2.5

• 5.0

• 13.3

• 26.7

What is the use of radioisotopes in the field of archaeology?

Apakah kegunaan radioisotop dalam bidang arkeologi?

• To determine the age of artifacts

  Untuk menentukan usia bahan purba

• To determine the mass of artifacts

  Untuk menentukan jisim bahan purba

• To determine the half-life of artifacts

  Untuk menentukan setengah hayat bagi bahan purba

• To determine the chemical content in artifacts

  Untuk menentukan kandungan kimia dalam bahan purba

A radioactive radiation is used to control the thickness of metal sheet in a metal manufacturing industry. Which of the following radioactive radiation is used?

Satu sinaran radioaktif digunakan untuk mengawal ketebalan kepingan logam dalam industri pembuatan logam. Antara sinaran radioaktif yang berikut, manakah digunakan?

• X-ray Sinar-X

• gamma ray Sinar gama

• alpha particles Zarah alfa

• beta particles Zarah beta

Which of the following is not the use of radioactive radiations?

Antara yang berikut, manakah bukan kegunaan sinaran radioaktif?

• To detect and treat the brain tumour

  Untuk mengesan dan mengubati tumor otak

• To determine the wear of engine parts

  Untuk menentukan kehausan bahagian enjin

• To detect object under surface of sea

  Untuk mengesan objek di bawah permukaan laut

• To detect leakage of underground water pipe

  Untuk mengesan kebocoran paip air bawah tanah

Radium-226 (Ra) has an atomic number of 88 and atomic mass 226. It is part of the Uranium decay series. Ra-226 decays into ____ by emitting an alpha partical

• Radon -222

• Lawrencium-226

• Radium-88

• Thorium-232

The % of the parent isotope remaining after 3 Half Lives.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

What is the Half life of this isotope?

• 5 seconds

• 10 seconds

• 15 seconds

• 20 seconds

Tags

NGSS.HS-PS1-8

What is Half-life?

• The amount of time it takes for some of the nuclei in a sample of the isotope to decay
• The amount of time it takes for half the electrons in a sample of the isotope to decay
• The amount of time it takes for half the nuclei in a sample of the isotope to decay
• the amount of time it takes to double the nuclei in a sample of the isotope to decay

Tags

NGSS.HS-PS1-8

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

• 100.0g
• 50.0g
• 12.5g
• 8.5g

Tags

CCSS.HSF.LE.A.4

After the third half-life, how much of the sample is left?

• 1/2
• 1/3
• 1/16
• 1/8

Tags

NGSS.HS-PS1-8