Answer : The chronological order events related to the formation of the universe with the stages in which they occurred are given below;
- Expansion from an infinitely hot point - Which is also called as the Planck era from which the big bang theory arrived. It is assumed that from the moment of initial expansion to
seconds afterwards, and many also refer that it was from an infinitely hot point. - Hydrogen fuses into helium - This was called as the era of Nucleosynthesis which resulted from the Fusion and it continued in the Era of Nucleosynthesis ( which is 0.001 seconds – 3 minutes)
- The first neutral atom begins to form - Era of atoms, it began in around 380,000 years – 1 billion years or so.
For better understanding please refer the attachment.
(Na2Cr2O7) all the numbers are bellow not over
Answer: Some are solid, some are gaseous, a few are liquid. Some are metallic: they have a peculiar lustre; some are coloured (like sulfur) or colourless. Some have a low density; some have a high density. Some are malleable and ductile; some are brittle. Some conduct electricity and heat well; some don’t.
Many metals tend to have structural uses. Nonmetallic elements less so.
Metals tend to have crystal forms featuring close-packed centro-symmetrical structures. Nonmetallic elements tend to have crystal structures featuring more open and directionally packed structures.
Some are especially toxic; some are essential to life; some are both depending on exposure level.
Most are stable; some are less so.
Some elements are highly reactive; some are almost inert (helium, neon, and argon may be completely inert in ambient conditions).
Many metals have basic oxides; quite a few oxides of nonmetallic elements form acids when they are dissolved in water. Some elements can go both ways.
There are many generalisations you can make about metallic and nonmetallic elements, and quite a few exceptions at the margins.
Explanation:
Answer:
B is the correct answer!
Explanation:
Balanced equation is Mg(OH)2 + 2 HCl = MgCl2 + 2 H2O
HCl is the limiting reactant because it gives the smaller amount of MgCl2 I did the math. This means you will be left with Mg(OH)2 since HCl completely runs out.
If HCl is the limiting reactant, Mg(OH)
2 is the excess reactant.
Mg(OH)
2 is a base, so the solution will be basic.
