Answer:
a fossil
Explanation:
Petrified wood is a fossil. It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, or another inorganic material such as opal.
Answer:

Explanation:
Hello there!
In this case, according to the combustion of octane:

We can see there is a 2:25 mole ratio of octane to oxygen; therefore, we can calculate the moles of oxygen via the following stoichiometric factor:

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Answer:
Sure, whats the question.
Explanation:
Answer:
A.
Explanation:
A change of position over time.
B is a vector and C is a distance.
Answer:
Molar mass of MgCO3 = 84.3 g/mol
Explanation:
What is the molar mass of magnesium carbonate.
Molar mass of a substance is defined as the mass of one mole of the substance expressed in grams hence its unit is gram per mole (g/mol)
MgCO3 is a compound and it's molar mass would be the sum of the molar masses of the elements that make up the compound. MgCO3 contains 1 atom of magnesium, one atom of carbon and 3 atoms of oxygen
Molar mass of Magnesium = 24.3g
Molar mass of Carbon =12g
Molar mass of Oxygen = 16g
Molar mass of MgCO3 will be
24.3 + 12 + 16×3
= 24.3 + 12 +48 = 84.3 g/mol
Molar mass of MgCO3 = 84.3 g/mol