Answer:
carbon and silicon
Explanation:
Various groups of elements in the periodic table have different outermost shell electron configurations. Actually, elements are classified into groups on the basis of the number of electrons on the outermost shell of those elements. All elements with the same number of electrons on their outermost shell belong to the same group in the periodic table.
For elements in group 14, they all have four electrons on their outermost shell. Their general outer electron configuration is ns2 np2 as shown in the question. Two prominent members of this group are carbon and silicon. This ns2 np2 is the ground state outer electron configuration of all group 14 elements in the periodic table.
Density = (mass) / (volume)
Density = (17.0 g) / (25.3 cm³) = 0.672 gm per cm³. (rounded)
The answer for this is 26.6°c
There are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
HOW TO CALCULATE MASS:
The mass of a substance can be calculated by multiplying the number of moles in the substance by its molecular mass.
However, given that the number of molecules in calcium hydroxide is 4.07 x 10¹⁵molecules, we need to calculate the number of moles in Ca(OH)2 as follows:
no. of moles of Ca(OH)2 = 4.07 x 10¹⁵ ÷ 6.02 × 10²³
no. of moles = 0.676 × 10-⁸
no. of moles = 6.76 × 10-⁹ moles.
Molar mass of Ca(OH)2 = 74.093 g/mol
Mass of Ca(OH)2 = 74.093 × 6.76 × 10-⁹ moles
Mass = 5.01 × 10-⁷grams.
Therefore, there are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.
Learn more about how to calculate mass at: brainly.com/question/8101390?referrer=searchResults
