Which of the following gases was NOT part of Earth’s original atmosphere?

Answer:

Calculate from Oxidation Number

The oxidation number of oxygen is -2, and the oxidation number of hydrogen is +1. Add together the oxidation numbers of all the atoms in the polyatomic ion. In the example, -2 +1 = -1. This is the charge on the polyatomic ion.

The boiling point of HBr is -66 (c)

Answer:

Every magnet has two sides: a north pole and a south pole. We use these names because if you hang a magnet from a thread, the magnet’s north pole points (almost) towards the north direction.

This is because the Earth’s core (its centre) is a large, weak magnet. Your little, strong magnet lines up with Earth’s magnetic core, so it points north. That’s how a magnetic compass works.

Answer:

Thermal heating and cooling

Explanation:

This process described results from thermal heating and cooling as a mechanism of mechanical weathering of rock bodies.

It is often more pronounced in the arid regions of the world where there is a significant difference between day and night temperatures. With mechanical weathering, rocks are broken down into fragments by physical disintegration. During the day, the high temperature causes the rock to expand significantly. At night, the rock contracts and on the long run, joints and fractures begins to appear on the rock surface.

Answer:

a very high melting point answer

1.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that reacts with water to produce a lilac flame

2.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element used as an inert atmosphere

3.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that has a valency of 3

4.Write a balanced chemical equation for the reaction between potassium and water. (Non-anonymous question). .
(1 Point)

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5.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element with a fixed valency of 2 that not is not in group 2

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