Answer: 
Explanation:
25.3% Mg
74.7% Cl
First step: change % to g
25.3g Mg
74.7g Cl
Second step: calculate g/mol of each compound. You can do this by using the atomic mass.


Third step: determine the lowest number and divide everything by it. Of the result, extract whole number only.


Fourth step: Write each compound with their respective number below.
This empirical formula should be: 
Answer:
Electric Current
This is a flow of electrons (such as the flow of electrons in a wire to light up a lamp).
Insulator
These stop the electricity from flowing (think rubber and glass).
Resistance
This is slowing the flow of electrons (the current) and where some of the electrons' energy gets converted into heat.
Conductor
These allow electricity to flow easily through them (think copper and aluminum).
The mass of He gas = 21.428 g
<h3>Further explanation</h3>
Given
120 liters of He gas
Required
the mass in grams
Solution
Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
Mol for 120 L :

Mass of He gas(MW=4 g/mol) :

Typical organic fertilizers include mineral sources, all animal waste including meat processing, manure, slurry, and guano, plant based fertilizers, such as compost, and biosolids.
Hope this helped :)
Answer:
Explanation:
Si tomamos en cuenta el peso molecular del agua, que es equivalente a:
1 Átomo de H₂O
O = 16 gr/mol
H = 1 gr/mol
H₂O = 18 gr/mol
Teóricamente sabemos que en 1 mol de H2O habrá 18 gr.
Para obtener los moles presentes en 1 mg de H₂O, (como 1 gr = 1000 mg), decimos:
1 mol H2O ………………………….. 18000 mg
X …………………………… 1 mg
X = 1 / 18000 = 5,56 X 10⁻⁵ moles de H20
Y para obtener la cantidad de moléculas presentes, de acuerdo a los moles, multiplicamos por el número de Avogadro (6,023 X 10²³ moléculas /mol)
Moléculas de H₂O = 5,56x 10⁻⁵ mol x 6,023 x 10²³
Moléculas de H₂O = 3,34488 x10¹⁹ moléculas de H₂O
En el copo de nieve habrá 3,34488 x 10¹⁹ moléculas de H₂O.
Espero que te sirva =)