Answer:
Cloudy nights can be warmer than clear nights because clouds trap heat absorbed by Earth during daylight hours.
The correct answer is Sulfur (S).
Sulfur has 6 valence electrons because it is located in Group 16 (or the sixth group over if you don’t count the transition metals). This means that one atom of sulfur has 6 electrons in its outermost shell out of 8 total “spots”, which you can count by counting the group numbers (excluding the transition metals) from Group 1 (with one valence electron) to Group 18 (the noble gases with full valence or outer shells).
By this same logic, Carbon (C) has 4 valence electrons and Cesium (Cs) has 1 valence electron, so neither of these is the correct answer.
Hope this helps!
<span>Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
</span>Mendeleev rewrote each edition of Principles of Chemistry<span>, including all new scientific data-particularly confirmations of the periodic law-and reanalyzing difficulties that had arisen to hinder its confirmation (inert gases, radioactivity, radioactive and </span>rare-earth elements<span>)
</span>he wanted to prove that he was right.
Answer:
about 0.9 mol
Explanation:
there are 22.990 g/mol of Na
20.7/22.99 = 0.900391 mol
about 0.9 mol
