Well, if the fossil is from the sea/is an ocean animal (for example a fish) , then you can say that the land was once underwater. If the fossil is from a desert, you can say that the land was once a desert, etc.
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance as distinct from a change in physical form or a nuclear reaction
Explanation:
please mark brainlest
In 1 mole of magnesium there are Avogadro's number of atoms are present.
Avogadro's number = 6.023 x 10²³
1 mole = 6.023 x 10²³ atoms
3.75 moles = 3.75 x 6.023 x 10²³
=2.26 x 10²⁴
So, in 3.75 moles of magnesium there are 2.26 x 10²⁴ atoms of magnesium are present.
Answer:
1. Mg (s) + 2Na+(aq) → 2Na(s) + Mg²⁺(aq)
2. 2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)
Explanation:
The net ionic equation of a reaction express only the chemical species that are involved in the reaction:
1. Mg (s) + Na2CrO4 (aq) → 2Na + MgCrO4(aq)
The ionic equation:
Mg (s) + 2Na+(aq) + CrO4²⁻ (aq) → 2Na + Mg²⁺ + CrO4²⁻(aq)
Subtracting the ions that don't change:
<h3>Mg (s) + 2Na+(aq) → 2Na + Mg²⁺</h3>
2. 2K(s) + Cd(NO3)2(aq) → 2KNO3(aq) + Cd(s)
The ionic equation:
2K(s) + Cd²⁺(aq) + 2NO3⁻(aq) → 2K⁺(aq) + 2NO3⁻(aq) + Cd(s)
Subtracting the ions that don't change:
<h3>2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)</h3>
A control group is the comparison group that helps to "make sure your experiment works." A control group is separated from the rest of the experiment and nothing happens to it kinda like a controlled variable. Controlled variables are the variables in a experiment that remains the same for example a temperature, time, type of products, etc..
Hope this helps!
