The elements in the periodice table are not listed in alphabetical order, because the arragement in rows (periods) and columns (groups or familes), in increasing order of atomic number (number of protons of the atoms) permits to explain similarities among the elements, trend in some properties, and even predict properties of unknown elements.
For example, the elements of the first group (family), called alkaline metals, all have 1 valence electron, have similar physical properties (ductibility, malleability, luster, thermal and electricity conductivity), react in similar way with water, show a trend in the atomic radii and in the ionization energy.
You can tell similar stories for other groups like, alkalyne earth metals, halogens and noble gases.
You can also tell trends in electroneativities, and atomic radii, for a row of elements, as per the order they are in the row.
So, the current array resulted very helpul for chemists to explain and predict the behavior and properties of the elements.
The correct answer is option d, that is, the solubility of a solid is highly dependent on temperature.
Solubility refers to the maximum amount of a component, which will get dissolved in a given concentration of solvent at a particular temperature. The temperature influences the solubility of both gases and solids. The temperature has a direct influence on solubility.
For most of the ionic solids, enhancing the temperature elevates how briskly the solution can be formed. With the increase in temperature, the movement of the solid particles takes place briskly that enhances the chances that they will associate with the majority of the solvent particles. This leads to enhancing the rate at which the solution takes place.
Answer:
The correct answer is "Fragment B likely has a higher Guanosine/Citosine content".
Explanation:
Guanosine/Citosine content, or GC content, refers to how many molecules of guanosine and citosine have a DNA fragment, respect to the content of adenine and thymine. The higher the GC content, the higher the temperature needed to denature the fragment of DNA. This happens because guanosine and citosine establish three hydrogen bonds, while adenine and thymine establish two hydrogen bonds when they bind together. Therefore, if fragment A and B are the same length, but at 89 C only fragment A is completely denatured, fragment B likely has a higher GC content.
Answer:
Sunlight penetrates the top layers of the ocean, so photosynthesis occurs there.
Explanation:
1) Chemical reactions produce new substances
Ans (d)
2) The symbol, Δ in a chemical reaction means that heat of supplied to the reaction.
Ans (a)
3) A skeleton equations does not show the reaction stoichiometry, i.e. the relative amounts of reactants and products.
Ans (d)
