Answer:
Igneous rock is the type of rock that forms as a result of cooling an crystallization
Explanation:
- Rocks are either sedimentary, igneous or metamorphic based on the chemical composition and the mode of formation.
- Igneous rocks are formed as a result of the cooling and crystallization of magma from volcanic eruptions.
- Igneous rocks are either intrusive, which form deep in the crust or extrusive which form on the surface of the earth.
- Sedimentary rocks are formed as a result of deposition, and cementation of sediments.
- Metamorphic rocks, on the other hand, are formed from the sedimentary and igneous rocks during the rock cycle.
The correct answer is 12.044 × 10²³ molecules.
The molecular mass of H₂S is 34 gram per mole.
Number of moles is determined by using the formula,
Number of moles = mass/molecular mass
Given mass is 68 grams, so no of moles will be,
68/34 = 2 moles
1 mole comprises 6.022 × 10²³ molecules, therefore, 2 moles will comprise = 6.022 × 10²³ × 2
= 12.044 × 10²³ molecules.
The features of Mendeleev's periodic table which helped us to understand whole periodic table was:
1) Atomic masses. - He arranged all the known elements in increasing order of their atomic mass, atomic mass is quite similar to atomic number (just plus number of neutrons) so, he did from simpler to complex elements, so he sorted his table.
2) Formation of oxides. - He checked for the formation of oxides, and the elements which can form similar oxides, he placed them in a same family (group)
3) Assumed for unknown element. - He just left the place for unknown element, it was the application of other two concepts which i described above, specific atomic mass with no oxides, would create an empty place. So, he just assumed, that element will be discovered in future & he had to left the place.
Hope this helps!