Day and night are due to the Earth rotating on its axis, not its orbiting around the sun. The term 'one day' is determined by the time the Earth takes to rotate once on its axis and includes both day time and night time.

5 0

3 years ago

Branliest to correct answer

ivann1987 [24]

The answer is D) The boy uses force to move the rock a distance

8 0

3 years ago

What is an example of an organ A.pancreas B.blood C.insulin D.knee

marissa [1.9K]

Answer: pancreas

Explanation:

4 0

3 years ago

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You have just isolated a new radioactive element. If you can determine its half-life, you will win the Nobel Prize in physics. Y

lbvjy [14]

Answer: 2.58 days

Explanation:

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

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = ?

t = age of sample = 6 days

a = initial amount of the reactant = 1 g

a - x = amount left after decay process = 0.2 g

a) to find the rate constant

$6=\frac{2.303}{k}\log\frac{1.0}{0.2}$

$k=\frac{2.303}{6}\log\frac{1.0}{0.2}$

$k=0.268days^{-1}$

b) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$t_{\frac{1}{2}}=\frac{0.693}{0.268}=2.58days$

The half life is 2.58 days

3 0

3 years ago