C. a metal.
Hope it helps!
Chemical property is when it's observed during a reaction in which the chemical composition or identity of the substance is changed. physical properties is when properties that do change the chemical nature of matter.
example for this is smell, color, freezing point, etc.
Answer:
C. H2SO4 I did the instruction
Answer:
c. A flat board tilted at an angle
Explanation:
form the looks of it, and i dont wanna sound like a flat earther her, cuz im not '-', but the best option here would be the flat board at an angle becasue the earth is tilted and isnt even like it said in the prompt.
Hope this helped and idrc about brainliest :)
First let us calculate for the rate constant k from the
formula:
k = ln(2) / t0.5
where t0.5 is the half life
k = ln(2) / 1.3x10^9 years
k = 5.33x10^-10 years-1
Then we use the formula:
A/Ao = e^-kt
where A/Ao is the amount remaining = 25% = 0.25, t is
time
Rearranging to get t:
t = ln(A/Ao) / -k
t = ln(0.25) / (-5.33x10^-10 years-1)
t = 2.6x10^9 years