Answer:
1. Considering the massive size of the structures, it is improbable to think that man is actually capable of building them.
2. And the intelligence and calculations needed for this construction is beyond the capacity of man, considering the age and times of the ancient Egyptians.
Explanation:
While Egyptologists and historians have, through years and years of research, have found evidence that it was actually the Egyptians that built them, there are also some people who held the belief that they are actually made and constructed by aliens. The humans of the ancient time that these structures were constructed were incapable of having the intelligent power and manpower and strength to carry out these works, with big blocks of stones and massive heavy structures to be made. However, the article "Who Built The Pyramids" shows the findings of Egyptologists Mark Lehner and Zahi Hawass who has worked to uncover the truth about these massive buildings of ancient years, trying to prove who actually built and how. They argued that, with all the workforce needed to actually bring about the construction of these structures, it is evident that the people of Egypt indeed were the workers and builders of these structures, and that too not as slaves (unlike many claims) but more as a sense of obligation to the king. And to refute the alien builder theory, there are definite proof that shows that it is humans and not aliens who built it. There are settlements that housed the workers, bone remains that have been examined by scientists and doctors, who have proved that humans and not aliens are the workers. Added to it, there seem to be no findings or even a shred of evidence too prove aliens have indeed been there, let alone construct that. Considering the massive structure of the pyramids, it is probable to think that man is incapable of constructing something like these, but like Lehner and Hawass has pointed out, there are lots of evidences to prove man actually built them. But there are still other group of theorists and believers that thinks aliens and not humans built them.
Answer:
Those who support the alien theory believe that the ancient Egyptians were very primitive. They argue that no blueprints of the pyramids have been found and that moving two-ton stones would have required alien technology.
Explanation:
C) Ba(ClO4)2. D) Ba(NO3)2
is insoluble in water.
Further Explanation:
Solubility rules
These help in predicting whether the given compound is soluble or insoluble in nature. Some of the solubility rules are as follows:
1. Group 1A compounds are soluble in nature.
2. All the common compounds of ammonium ion and all acetates, chlorides, nitrates, bromides, iodides, and perchlorates are soluble in nature. But the ions whose chlorides, bromides, and iodides are not soluble are ,
,
and
.
3. All common fluorides, except for and group 2A fluorides are soluble. Also, all sulfates except
,
,
,
and
are soluble.
4. All common metal hydroxides except ,
,
and hydroxides of group 1A and that of transition metals are insoluble in nature.
5. All carbonates are insoluble in nature, except for sodium, potassium and ammonium.
6. Salts having ions like ,
or
are generally soluble except those of
,
and
.
7. Group 1A and group 2A perchlorates are soluble in nature.
8. All sulfates of metals are soluble, except for lead, mercury (I), barium, and calcium sulfates.
9. The salts having nitrate ions are soluble in nature.
According to the solubility rules, only carbonates of sodium, potassium and ammonium are soluble in nature. So barium carbonate is insoluble in nature. But chlorides, nitrates and perchlorates of barium are soluble in water. Therefore option A is the correct answer.
Learn more:
Answer details:
Grade: Senior School
Chapter: Chemical reaction and equation
Subject: Chemistry
Keywords: barium, water, insoluble, solubility rules, soluble, insoluble, water, BaCO3.
BaCO₃ is generally considered insoluble in water. Carbonates are often insoluble, except for some alkali metals and ammonium carbonates. Therefore, option A is correct.
The solubility of salt depends on its nature and the interactions between its ions and water molecules. In this case, determine the solubility of each salt by considering the common solubility rules.
BaCl₂ is soluble in water. Chlorides (Cl-) are mostly soluble except for a few exceptions, such as silver chloride, lead chloride, and mercury(I) chloride.
Ba(ClO₄)₂ is soluble in water. Perchlorates (ClO4-) are typically soluble.
Ba(NO₃)₂ is soluble in water. Nitrates (NO3-) are mostly soluble.
Based on the solubility rules, the salt that is insoluble in water is BaCO₃ (barium carbonate).
To learn more about the solubility, follow the link:
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metal and nonmetal
metalloid and nonmetal
two metals
Answer: The correct answer is metal and non-metal.
Explanation:
Elements are mainly divided into 3 classes in the periodic table.
1.) Metals: The element which lie on the left side of the periodic table are mainly metals. These elements loose electron easily and form positively charged species. These elements are present in the highest proportion in the periodic table.
2.) Non-metals: The elements which lie on the right side of the periodic table are considered as non-metals. These elements gain electrons easily and form negatively charged species.
3.) Metalloids: These lie between metals and non-metals and show the properties of both metals and non-metals.
Copper lie in the period 4 and group 11 of the periodic table and it can easily loose electron and hence, it is considered as a metal.
Chlorine lie in the period 3 and group 17 of the periodic table and it can easily gain electron and hence, considered as a non-metal.
Therefore, the correct answer is metal and non-metal.
Water droplets begin to fall back to Earth from clouds.
B
Water vapor transfers back to water droplets or ice crystals.
Small particles form and bump into each other to form clouds.
D
The sun turns water into water vapor as it heats Earth's surface.
Answer:
B. Water vapor transfers back to water droplets or ice crystals.
Explanation:
Its What I know ehe sorry in advance if its wrong :))