Niobium-91 has a half of 680 years. After 2.040 years, how much niobium-91 will remain from a 750.00-g sample

Niobium-91 will remain 93.75 g

Further explanation

The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.  

Usually radioactive elements have an unstable atomic nucleus.  

The main particles are emitted by radioactive elements so that they generally decay are alpha (α), beta (β) and gamma (γ) particles  

General formulas used in decay:  

T = duration of decay  

t 1/2 = half-life  

N₀ = the number of initial radioactive atoms  

Nt = the number of radioactive atoms left after decaying during T time  

Half life -t1/2 of Niobium-91 =680 years

T=duration time=2040 years

No=initial sample=750 g

Niobium-91 will remain :

Ithink 2 is the correct

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .