Each period represents once a principal energy level has been reached for an element.
<span>a) Table salt: it is a compound. A compound is a combination of atoms in fixed proportions.Table salt is NaCl, which means that table salt is a compound of 1 atom of Na and 1 atom of Cl and not other thing. b) Blood: is an homogeneous mixture: it is a mixture of many compounds which can not be easily distinguished or separated, you need microscopes or very special physical methods to distinguish or separate the different compounds of blood. d) Steel: it is a special king of homogeneous mixture (it is called an alloy) which, as in the case of blood, cannot be distinguished or separated easily. d) Planet earth: it is a heterogeneous mixture. You can easily distinguish many of the compounds of the planet Earth: water, oxygen, carbon,...</span><span />
Answer:
In general, the energy needed to remove an electron (the ionization energy) increases as the atomic number increases across a period.
Explanation:
Each additional proton increases the attraction between the nucleus and the electron.
Thus, it takes more energy to remove an electron as you add extra protons.
Answer:
For enlightenment, development and making people understand the usefulness of the product
