The length of a year is equivalent to the time it takes for one.. (pls help I honestly forgot )

Mantle convection is a process of that creates circular currents in the asthenosphere. As a result, the plates slowly move.

LUCKY_DIMON [66]

Answer:

<em>Rigid plates that move around Earth's surface is called tectonic plates. </em>

Explanation:

Lithosphere is rigid and relatively cold and is the outer surface of the planet. The convective motions of maintenance break the lithosphere into plates.

This place that a form can move in any direction, can move towards each other, can move away and push each other which is the reason for formation of mountains for shifting of continents for making of ocean basin.

8 0

3 years ago

If we start with 1.000 g of strontium-90, 0.805 g will remain after 9.00 yr. This means that the of strontium-90 is ________ yr.

lesantik [10]

The question is incomplete, here is the complete question.

If we start with 1.000 g of strontium-90, 0.805 g will remain after 9.00 yr. This means that the half-life of strontium-90 is ________ yr.

a. 28.8 b. 30.9 c. 35.4 d. 32.2

Answer : The half-life of strontium-90 is 28.8 years.

Explanation :

This is a type of radioactive decay and all radioactive decays follow first order kinetics.

First we have to calculate the rate constant.

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

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

where,

k = rate constant

t = time taken for decay process = 9.00 year

a = initial amount or moles of the reactant = 1.000 g

a - x = amount or moles left after decay process = 0.805 g

Putting values in above equation, we get:

$k=\frac{2.303}{9.00}\log\frac{1.00}{0.805}$

$k=0.0241\text{ year}^{-1}$

To calculate the half-life, we use the formula :

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

$0.0241\text{ year}^{-1}=\frac{0.693}{t_{1/2}}$

$t_{1/2}=28.8\text{ years}$

Therefore, the half-life of strontium-90 is 28.8 years.

5 0

3 years ago

in the cell, newely made proteins move directly from the ribosomes into the rough _____ _____, where they are chemically modifie

olga nikolaevna [1]

Answer:

endoplasmic reticulum

Explanation:

there it is

8 0

3 years ago

What is the representative particle for silicon

valentina_108 [34]

<span>The representative particle for silicon is atom of silicon.
</span>Representative particles can be atoms, molecules, formula units or ions. Representative particles depend on the nature of the substance. Silicon is chemical element made of atoms.
For sodium chloride (NaCl) for example, representative particles are ions.

7 0

3 years ago

The map shows the global distribution of amphibians. The number of different amphibian species found in an area is

harkovskaia [24]

What's up? im not gonna type a whole thing but you probably could make do with this info:

amphibians need water and a moist environment. north africa will constantly have droughts/low amounts of water, so amphibians could not survive there. in Antarctica, it is much too cold and as cold blooded animals they would simply freeze to death

best of luck with your studies

8 0

2 years ago