The half-life of element X is 500 years. If there are initially 8 g of X, how much will remain after 1500 years

1 g

Explanation:

From the formula;

N/No = (1/2)^t/t1/2

Where;

N= mass of radioactive element left after a time t = the unknown

No= mass of radioactive element originally present in the sample = 8g

t= time taken for N mass of the sample to remain = 1500

t1/2= half-life of the radioactive element = 500 years

Substituting values, we have;

N/8 = (1/2)^1500/500

N/8 = (1/2)^3

N/8 = 1/8

N= 1/8 ×8

N= 1 g

Therefore; mass of radioactive element left after 1500 years is 1 g

the dissociation of nickel hydroxide is follows:

the concentration of hydroxide ion is

the equilibrium constant value of nickel hydroxide is = 6.1 * 10^-^1^6 and thus equilibrium equation can be written as:

thus, concentration of ni is 0.23 * 10^-^4 mol /l

qualitative observation deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they do not involve measurements or numbers. for instance, colors, shapes, and textures of objects are all qualitative observations.