That statement is true
it was easy to organize 'all' the elements in a group of threes because back then they only knew about 15 - 20 elements
hope this helps
Answer:
Gallon (US) to Milliliter Conversion Table
Gallon (US) [gal (US)] Milliliter [mL]
1 gal (US) 3785.411784 mL
2 gal (US) 7570.823568 mL
3 gal (US) 11356.235352 mL
5 gal (US) 18927.05892 mL
Answer:
All atoms heavier than barium
Explanation:
In the periodic table, elements are divided into blocks. We have the;
s- block elements
p- block elements
d- block elements
f- block elements
However, immediately after Barium, we now encounter elements that have f-orbitals. Barium possesses a fully filled d-orbital. Hence after it, we see elements with 4f and 5f orbitals called the Lanthanides and actinides. The elements following the lanthanide and actinide series possess completely filled f-orbitals as inner orbitals.
Hence elements heavier than barium all possess f-orbitals.
Chemical reactions that release energy will not occur without a source of energy. So the answer is release.