Dobereiner's triads were an early attempt to sort the elements into some logical order by their physical properties. The appearance and reactions of the elements in a triad were similar to each other. He showed that in each triad the mean of the lightest and heaviest atomic weights approximated the atomic weight of the middle element.
Answer:
The answer is the last one
Explanation:
1. Give
2.me
3. Brainliest
4.please
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Below are the choices that can be found from other sources.
The answer is C endothermic and exothermic
<span>a. exothermic and exothermic
b. exothermic and endothermic
c. endothermic and exothermic
d. endothermic and endothermic</span>
Answer:
Na₂O is the formula for the ionic compound "sodium oxide".
It has 2 sodium atoms and 1 oxygen atom.
The number of atoms for an element are written as a subscript after the element. "1" subscripts are not written.
The names of the elements are found on the periodic table.
