Aidez moi s’il vous plaît je bloque sur cette exercice : Le trophée de la Coupe du
monde de football pèse 6,175 kg.
Il est en or 18 carats.
Donnée Pourcentage massique
d'or pur dans l'or 18
carats : 75 %
a. Calculer le nombre d'atomes d'or.
b. Calculer la quantité de matière
d'or correspondante.

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z

How to tell if a molecule is polar or nonpolar with electronegativity

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )