It’s science can some plz help me
1 answer:
You might be interested in
Answer: The tree died 9709.46 years before.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process =
a) to find rate constant
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
b) to know the age
The tree died 9709.46 years before.
Answer:
the correct answer is option 'b': More than
Explanation:
The 2 situations are represented in the attached figures below
When an object is placed in air it is acted upon by force of gravity of earth which is measured as weight of the object.
While as when any object is submerged partially or completely in any fluid the fluid exerts a force in upward direction and this force is known as force of buoyancy and it's magnitude is given by Archimedes law as equal to the weight of the fluid that the body displaces, hence the effective force in the downward direction direction thus the apparent weight of the object in water decreases.
Answer:
= 0.5 moles of water
Answer: 72 grams of are needed to completely burn 19.7 g
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number of particles.
To calculate the number of moles, we use the equation:
Putting in the values we get:
According to stoichiometry:
1 mole of requires 5 moles of oxygen
0.45 moles of require=
moles of oxygen
Mass of
72 grams of are needed to completely burn 19.7 g