Un element Y inconnue appartient a la meme periode que le magnesium (12Mg) et son schema de Lewis est: Y. a) ecrire la configuration electronique de l'atome Mg.
b) identifier l'element Y.
c) un element X appartient a la meme periode que Y et a la meme valence. Identifer X.
d) identifier la nature de la liaison qui pourrait lier (X) et (Y)

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)

Is a pencil falling to the floor anon contact force, a force, or a contact force

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory