Answer:
Explanation:
In 1789, Antoine Lavoisier published a list of 33 chemical elements. Although Lavoisier grouped the elements into gases, metals, non-metals, and earths, chemists spent the following century searching for a more precise classification scheme. In 1829, Johann Wolfgang Döbereiner observed that many of the elements could be grouped into triads (groups of three) based on their chemical properties. Lithium, sodium, and potassium, for example, were grouped together as being soft, reactive metals. Döbereiner also observed that, when arranged by atomic weight, the second member of each triad was roughly the average of the first and the third.[19] This became known as the Law of Triads.[20] German chemist Leopold Gmelin worked with this system, and by 1843 he had identified ten triads, three groups of four, and one group of five. Jean Baptiste Dumas published work in 1857 describing relationships between various groups of metals. Although various chemists were able to identify relationships between small groups of elements, they had yet to build one scheme that encompassed them all.[19]
Answer:
The diagonal of the parallelogram PBCA is the resultant force R, which forms two scalene triangles with the forces F1 and F2. Since the sum of all the angles within a triangle is 180°, we can write γ function of α and β. The resultant force can also be calculated analytical, using force projections.
Explanation:
Please give thanks to all my answers and please mark as brilliant and please follow me
Answer;
North east
Explanation;
North East region of the country has diverse political trends.
No single political party gets majority votes in the North East region.
Every election the winning candidate lose the election which does not allow political analysts to guess the outcome of a forthcoming election. Many political parties share power in the North East.
Answer B
Explanation:
You are depressed if you are discouraged by life
Tectonic plates under the ground ,either go on top of each other or crash.