Its 470mg k dude or dudette
Answer:
Argon is an element on the periodic table. It is a member of the noble gasses, meaning that it is a monoatomic pure gas. In other words, argon gas particles are simply pure single atoms of argon. ... Finally, water is a polyatomic molecule H2O composed of two atoms of hydrogen and one atom of oxygen.
Explanation:
Answer : The concentration of A after 80 min is, 0.100 M
Explanation :
Half-life = 20 min
First we have to calculate the rate constant, we use the formula :



Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = 80 min
a = initial amount of the reactant = 1.6 M
a - x = amount left after decay process = ?
Now put all the given values in above equation, we get


Therefore, the concentration of A after 80 min is, 0.100 M
Should be 18, well i guess I have to have 20 characters so good luck