Half-life

Technetium's atomic number is

(a)  

How many neutrons would Technetium-99 have?

(a)  

Technetium-99 undergoes beta decay, meaning when it transmutes, it emits

When Technetium-99 transmutates, its nuclei would turn into

Technetium-99 has a half-life of 6 hours. How much of a 0.5g sample of technetium-99 would remain after it has been undergoing radioactive decay for 24 hours? (a)   g (rounded to 2 d.p.)

Suppose you leave a 0.2g sample of technetium-99 in a cupboard overnight. Technetium transmutates into ruthenium. How long would the sample of technetium have been left in the cupboard for, if there was 0.175g of ruthenium present the next day? (a)   hours

Smoke detectors contain radioactive americium. The americium emits an alpha particle when it transmutates. Alpha particles are

The americium in smoke detectors decays into neptunium-237. Which isotope of americium is being used here?

If a sample of americium-241 is left to undergo alpha decay, the transmutation is fairly slow. After 1296 years, 87.5% of the americium will be gone. What is the half-life of americium? (a)   years