Given :
An atom of a certain element has 12 protons, 14 neutrons, and 2 valence electrons.
To Find :
The name of this element.
Solution :
We know, element with atomic number ( number of protons ) 12 and valance electrons is Magnesium.
Now, isotope of magnesium of proton with 14 neutrons is Mg-16 .
Therefore, name of element is Mg-16 .
Hence, this is the required solution.
umm how do you begin answering that ??
Option D
A precipitate is the term for a solid that forms when two solutions are mixed
<u>Explanation:</u>
A solid set from a couple of solutions is termed a precipitate. A precipitate is an unsolved solid that makes when a pair of solutions are fused and react chemically. Unsolvable means that the solid will not melt. When the effect transpires in a liquid solution, the solid developed is denominated the 'precipitate'.
The substance that generates the solid to make is termed the 'precipitant'. Seldom the development of a precipitate symbolizes the existence of a chemical reaction. Precipitation may additionally transpire immediately from a supersaturated solution.
Density of the gas is 3.05 × 10⁻³ g / cm³.
<u>Explanation:</u>
Volume of the cylinder = π r² h
where r is the radius and h is the height of the height or the length of the glass tube.
Here r = 4 cm and h = 27.4 cm
Volume of the cylinder = 3.14 × 4 × 4 × 27.4 = 1376.6 cm³
We have to find the mass of the gas by subtracting the mass of the tube filled with the substance from the mass of the empty tube.
Mass of the substance = 258.5 - 254.3 = 4.2 g
We have to find the density using the formula as,
Plugin the values as,
= 3.05 × 10⁻³ g / cm³
So the Density of the gas is 3.05 × 10⁻³ g / cm³.
