The alkali metals are so reactive that they are never found in nature in elemental form. Although some of their ores are abundant, isolating them from their ores is somewhat difficult. For these reasons, the group 1 elements were unknown until the early 19th century, when Sir Humphry Davy first prepared sodium (Na) and potassium (K) by passing an electric current through molten alkalis. (The ashes produced by the combustion of wood are largely composed of potassium and sodium carbonate.) Lithium (Li) was discovered 10 years later when the Swedish chemist Johan Arfwedson was studying the composition of a new Brazilian mineral. Cesium (Cs) and rubidium (Rb) were not discovered until the 1860s, when Robert Bunsen conducted a systematic search for new elements. Known to chemistry students as the inventor of the Bunsen burner, Bunsen’s spectroscopic studies of ores showed sky blue and deep red emission lines that he attributed to two new elements, Cs and Rb, respectively. Francium (Fr) is found in only trace amounts in nature, so our knowledge of its chemistry is limited. All the isotopes of Fr have very short half-lives, in contrast to the other elements in group 1.
I know it's only 5 points but heres the answer
<span>1. It depends what type of method you are using. if it is Height x Width x Length then it will not work for an irregular shape because it has extra pieces that would not be included.
2. The second method would work for both regular and irregular shapes because you would have to know or find out the volume of the regular shape to get the volume for the irregular shape.
3. It also depends on what you are doing, if you are doing a regular shape then use the first method, if it's an irregular shape then use the second method, if you do the maths correctly both should give you an accurate answer for what you want to achieve.
4. No, because the sugar would dissolve.
5. No, on this case the displacement method would not work because of the weight difference
I hope this helps you a bit.</span>
Answer:
We, apply equal torque to both spheres and measure their final angular acceleration.
Explanation:
The moment of Inertia of solid sphere will be (2/5)mr²
The moment of Inertia of hollow sphere will be (2/3)mr²
Thus, the moment of inertia of inertia of hollow sphere is greater than that of the solid sphere. Since, the torque is equal to the product of moment of inertia and angular acceleration.
Therefore, we design a test such that we apply the same amount of torque to both the spheres. Due to greater amount of moment of inertia the hollow sphere will acquire high angular acceleration, while solid sphere will acquire low angular acceleration.
Hence, by the measurement of final angular acceleration, we can determine, which sphere is which.
<span>The molecular formula for phosphoric acid is H3PO4 and has 97.994 grams per mol. In a sample of 658 grams of phosphoric acid, there are 6.71 mols of phosphoric acid.</span>
Based on atomic properties and structure:
- Isotopes have the same proton number(atomic number) but different neutron numbers.
- An atom of barium has 56 protons and 56 neutrons in order to maintain electrical neutrality.
- The mass number of an atom is determined by the sum of protons and neutrons.
<h3>What are isotopes?</h3>
Isotopes are atoms of an element having the same atomic number but different mass numbers.
The difference in mass number is dues to different neutron numbers.
However, because they have the same proton number, they are atoms of the same element.
Neutral atoms contains equal number of protons and electrons.
An atom of barium has 56 protons and 56 neutrons in order to maintain electrical neutrality.
The mass number of an atom is determined by the sum of protons and neutrons.
Learn more about isotopes at: brainly.com/question/14220416