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WINSTONCH [101]
3 years ago
14

HOW do we know about life from before human time?

Chemistry
1 answer:
GenaCL600 [577]3 years ago
8 0

B fossils

hope this helps :)

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If you want 2 miles of Silver (Ag) from the reaction below, how many grams of copper should you start with? Reaction: Cu + 2AgNO
RSB [31]

Answer:

You should start with 63.54 grams of copper.

Explanation:

The chemical reactions are processes in which the nature of the substances changes, that is, from some initial substances called reactants, totally different ones called products are obtained.

In the chemical reaction, the formulas of reagents and products appear preceded by numbers (the stoichiometric coefficients) that indicate the proportions according to which the transformation occurs. So you can say that stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships that are established are MOLAR relationships between the compounds or elements that make up the chemical equation: always in MOLES.

The stoichiometric coefficients of a chemical equation are due to the fact that the atoms present before the reaction must be the same after the reaction, although they will have been rearranged to produce new substances.

If you want 2 moles of silver (Ag), for stoichiometry of the reaction you need a moles of copper Cu. Being the molar mass of copper Cu 63.54 g / mole, then:

1 mole*63.54 g/mole= 63.54 g

<u><em> You should start with 63.54 grams of copper.</em></u>

<u><em></em></u>

8 0
2 years ago
1. When frequency increases energy:
liraira [26]
B

When frequency increases, as does the energy, but wavelength decreases. It also works vise versa; if wavelength were to increase, its frequency and energy will decrease.
8 0
2 years ago
How did plastics become the material of choice for so many varied applications?
Maslowich

Answer:

people as: it Is less expensive. easy to carry

7 0
3 years ago
What is the specific heat of a substance if 1450 calories are required to raise the temperature of a 240g sample by 20℃?
bazaltina [42]

Answer:

6960 J/kg°C

Explanation:

specific heat= mass×specific heat capacity×increase in temperature

specific heat= 0.240×1450×20= 6960 J/kg°C

hope it helps!

5 0
2 years ago
The maximum number of orbits in an atom is _____.<br><br> -three<br> -five<br> -seven<br> -nine
marissa [1.9K]
Seven
Elements do not contain more than 7 electron shells.
4 0
3 years ago
Read 2 more answers
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