Answer:
A)
Explanation:
Entre todos esas materias el hidrógeno es el más fuerte
Answer:
9000 BC
Explanation:
Although various copper tools and decorative items dating back as early as 9000 BCE have been discovered, archaeological evidence suggests that it was the early Mesopotamians who, around 5000 to 6000 years ago, were the first to fully harness the ability to extract and work with copper.
The correct answers are as follows:
1. MgSO4 + 2NH4OH = [NH4]2SO4 + Mg[OH]2.
This chemical equation implies that, one molecule of magnesium sulphate react with two molecules of ammonium hydroxide to give rise to one molecule of ammonium sulphate and one molecule of magnesium hydroxide.
2. The reaction between magnesium sulphate and ammonia is a DOUBLE REPLACEMENT REACTION.
A double replacement reaction is a type of reaction in which the two chemical substances which take part in the reaction switch their ions in such a way that two new products are formed. In the reaction of magnesium sulphate and ammonia, the magnesium sulphate gives its SO4 ion to ammonia and take the OH ion of the ammonia instead.
3. The epsom salt and the ammonia reacted. This is made obvious by the chemical reaction which was generated by their combination. On the edge of the penny used, one can see that there is a colour change, this shows that a chemical reaction occur.
Answer: C. Convection currents in the asthenosphere.
Explanation: Most geologists think that the movement of Earth's plates is caused by convection currents in the asthenosphere.
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