Data analysis has two prominent methods: qualitative research and quantitative research. Each method has their own techniques. Interviews and observations are forms of qualitative research, while experiments and surveys are quantitative research.
Answer:
2moles of H2
Explanation:
First, let us generate a balanced equation for the reaction between calcium and water. This is illustrated below:
Ca + 2H20 —> Ca(OH)2 + H2
From the equation,
2moles of H2O produced 1mole of H2.
Therefore 4moles of H2O will produce = 4/2 = 2moles of H2.
Answer:
280 electrons
Explanation:
The number of electrons in each energy level are determine by using following formula:
2n²
Here "n' is the energy level. we will put the energy level number in place of "n" and number of electrons will easily found.
Principle energy levels number of electrons
1 2n² = 2(1)²= 2
2 2n² = 2(2)²= 8
3 2n² = 2(3)²= 18
4 2n² = 2(4)²= 32
5 2n² = 2(5)²= 50
6 2n² = 2(6)²= 72
7 2n² = 2(7)²= 98
So the total number of electrons in first seven energy levels will be the sum of the number of electrons in each energy levels.
2+8+18+32+50+72+98 = 280 electrons
Answer:
Dark matter also called baronic matter is the matter that makes up 27% of the universe.
In 1933 it was determined as that mass that cannot be seen, that is, the non-visible mass of outer space.
Dark matter also plays a central role in the formation of structures and the evolution of galaxies and has measurable effects on the anisotropy of cosmic microwave background radiation. The composition of this matter is unknown today.
The dark matter component has considerably more mass than the "visible" component of the Universe.
Explanation:
There are certain researchers who say that the appearance of dark matter was before the appearance of the big bang.
A relevant fact of this matter is that dark matter exerts gravity, and that gravity affects the movements of objects.
Despite the fact that nothing is known about its origin, astronomers have amply demonstrated that dark matter plays a determining role in the formation of galaxies and galactic clusters, which could not maintain their cohesion without its existence, but many doubt that it is the remainder / remnant or product of a big bang.