Potassium -40half life = 1.28 ×10∧9.
Radioisotope can be used to determine the age of fossils, to treat skin disease, to sterilize foodstuffs, and also to sterilize surgical instruments.
Radioisotope dating is a way to estimate a fossil's age by a method of analyzing the elemental isotopes which are within the rocks which it is in.
Solution:
Benzoic acid is C6H5COOH
In finding pH
C6H5COOH(aq) <=> C6H5COO^- + H^+ pKa = 4.19, pKa = -logKa so Ka = 10^(-4.19)
Ka = 6.45 x 10^-6
[C6H5COO^-] = x = [H^+]; [C6H5COOH] = 0.5 - x (we are able to make an estimate of [C6H5COOH] = 0.5.
Ka = [H^+][C6H5COO^-]/[C6H5COOH] = x^2/(0.5 - x) = 6.45 x 10^-6
Now,
According to the quadratic equation. x^2 = 3.23 x 10^-5 - 6.45 x 10^-6x
x^2 + (6.45 x 10^-6)x - 3.23 x 10^-5 = 0
enter a = 1, b = 0.00000645, c = 0.0000323
x = 5.68 x 10^-3 = 0.00568 M expression is [C6H5COOH] = 0.5 M is the correct answer.
[H^+] = 0.00568 M, so pH = -log(0.00568 M ) = 2.25
This is the required solution.
Answer:
P = 8000 Kg m/s
When speed is increased to 50 m/s,
P = 40,000 kg. m/s
Explanation:
Given data:
Mass = 800 Kg
Velocity = 10 m/s
Momentum = ?
Speed increased = 50 m/s
Momentum = ?
Solution:
Formula:
P = mv
P = 800 kg× 10 m/s
P = 8000 Kg m/s
When speed is increased to 50 m/s.
P = mv
P = 800 kg× 50 m/s
P = 40,000 kg. m/s
Answer:
To find the noble gas notation, you first take the noble gas before the element you’re trying to find the notation for. In this case, the noble gas before Calcium is Argon. You put the symbol for Argon in square brackets, and then you write out the rest of the notation as you would normally.
This would look like [Ar]4s^2
The 4s^2 is because Calcium is the second element in the 4s columns (refer to the diagram)
Hope this helps :)
If you’ve ever smoked a joint or eaten a pot-laced brownie, you’re hardly alone: More than 1 in 3 people in America have tried marijuanaat one point in their lives.
Though occasional use isn’t usually harmful, pot can affect your body and mind any time it gets into your system. Here’s what you need to know.
Physical Effects
Marijuana comes from the hemp plant <span>Cannabis sativa. </span>It has an active ingredient called THC that makes you feel high. THC and other compounds in marijuana can also affect the way your body works.
