The law of conservation of mass applies to both cases, the following will explain how:
1. When 50 g of sugar undergoes a physical change, say for example dissolving or melting, the amount of sugar in the solution or melted form will also be 50 grams. This shows that the mass before and after the change was the same, in accordance to the law of conservation of mass.
2. When the magnesium strip is burned, this is a chemical reaction. The problem is that we only measure the mass of one of the substances involved in the reaction, the magnesium strip, which makes it seem like the mass has increased. Actually, during burning, the magnesium combines with oxygen in the air. This oxygen was present before the reaction, we just did not measure it. And after the reaction it is present in the form of product. Therefore, mass is still conserved.
The number Beryllium chloride consumed is calculated as follows
write equation for reaction
that is BeCl2 + Mg -----> MgCl2 +Be
find the moles of MgCl2 produced
moles =mass/molar mass of MgCl2
= 987.5g/95 = 10.39 moles
by use of mole ratio between BeCl2 to Mgcl2 which 1:1 therefore the moles of BeCl2 is also 10.39moles
mass of BeCl2 = moles x molar mass
that is 10.39 x80 = 831.2
Answer:
Los elementos de la tabla periódica se distribuyen sobre la base de similitudes.
Explicación:
Los diferentes tipos de elementos se distribuyen en 8 grupos de tabla periódica en función de sus propiedades. Los elementos que tienen propiedades similares se colocan en el mismo grupo. Por ejemplo, el primer grupo de la tabla periódica son los metales alcalinos. Todos los metales alcalinos tienen algunas propiedades similares, es decir, un electrón en su capa más externa, alta reactividad y forma metálica, mientras que, por otro lado, los ocho elementos del grupo son gases nobles que tienen una capa más externa completa y no tienen reactividad.
Answer:
neither accurate nor precise
Explanation:
Accuracy is the ability to give the same result on different measurements made under the same conditions or to give the desired result accurately, therefore, as observed in the image, the results are not accurate, since they are all different.
They are not precise either, since the precision is the degree of agreement between the independent results of a measurement, obtained under stipulated conditions, be it repeatability, reproducibility or intermediate.
Explanation:
Iron atom is been oxidised as it losses 2 electron to form 2 + ion.
