1) deep trenches
2) active volcanoes
3) arcs of islands along the tectonic boundaries
4) in some cases, mountain ranges
Answer:
D
Explanation:
The greater the distance apart, the lesser the gravitational force between the objects
Explanation:
A student flips four different coins at the same time. Which choice shows all of the possibilities for the results of the coin toss? (H = heads, T = tails)
A HH, TT, HT, TH
B HHHT, HTTT, HHTT
C HHH, TTT, HTH, HTT
D HHHH, HTHH, HTTH, HTTT, TTTT
Answer:
Group 18th
Explanation:
The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.
<em>Answer: </em>D
<em>Explanation:</em>
chemical formula of methane: CH4
electron configuration of C: 2,4
electron configuration of H: 1
there are 4 hydrogen atoms that donated 1 electron each to C
therefore it's D.
