Wet barometer - The tool works by measuring atmospheric pressure to predict incoming weather. Since the glass is only filled halfway with water, the other half is exposed to the atmosphere. When the outdoor atmospheric pressure rises, the pressure in the glass decreases, and causes the water to move down the spout.
Dry barometer - A Torricellian barometer (sometimes called a mercury barometer) is an inverted (upside-down) glass tube standing in a bath of mercury. Air pressure pushes down on the surface of the mercury, making some rise up the tube. The greater the air pressure, the higher the mercury rises.
I hope this helps!
The complete statement made by Stephen Hawking is: "though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival of the species."
If one looks at our history, there are some events that defy our capacity for logical thinking. One would think that, as we possess this capacity, we would be able to direct our decisions towards the survival of the human species.
However, in many cases greed and the desire for personal gain have taken precedence. One good example was the burning of the great library of Alexandria, one of the most significant libraries in the ancient world. This magnificent collection was lost during the siege of Alexandria, when Julius Caesar set on fire the ships in the harbor.
Another example is the atomic bomb, when science has been used to invent one of the most destructive weapons known to us. Atomic warfare is still a threat that may end all life on Earth.
Furthermore, the greed of some corporations has led to multiple ecological catastrophes that endanger not only other species but our own future as well. One example is the Bhopal gas leak in India, where in 1984, due to poor maintenance, the chemical plant released 30 metric tons of methyl isocyanite into the atmosphere.
Answer:
In the n=1 energy level, the atom has 2 electrons
Explanation:
Electrons orbit the nucleus of an atom in multiple rings (energy levels). The first ring of the electron can only hold 2 electrons. After that, electrons are added to the second ring. Excluding the first ring, all other rings can hold a maximum of 8 electrons.
For example, Oxygen is an atom with 6 electrons. The first energy level contains 2 electrons, and the second energy level contains 4 electrons. The second energy level has room for up to 4 more electrons.
In your example of an atom with 15 electrons, there would be 2 electrons in the first ring, 8 electrons in the second ring, and 5 electrons in the third and final ring.
To summarize, all atoms have a first energy level containing 2 electrons, and all other energy levels can contain 8 electrons. This is true no matter the number of electrons.
