“i believe the identity of the unknown element is sodium, in part because...
a. not reliable because many metals are gray and several react with water
b. reliable because the author believes the statement to be valid
c. not reliable because the identity of the element was not originally known
d. reliable because it deals with science topics such as metals and chemical reactivity
(can you tell me if I'm right)
Option (A) is the correct answer.
Since there are many elements in the periodic table which are grey in color and they are also able to react with water.
For example, silicon, iron, cobalt, nickel, tungsten etc are all grey in color.
Therefore, when we are given an unknown element which is grey in color and reacts with water then we cannot exactly tell which element it is unless some more of its specific properties are given.
Thus, we can conclude that the correct statement will be, not reliable because many metals are gray and several react with water.
c8h10 is your answerr
assuming that your periodic table has eighteen columns, you should highlight the four elements in the third column from the left of the table.explanation
neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.
by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.
potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.
a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.