What is true about most higher-grade metallic ores? O They are usually found deep below Earth's surface-more than 1,000 ft underground

O Most of them can be extracted using the placer method.

O Most of them can be extracted without requiring
blasting.

O They are usually found very close to Earth's surface less than 1,000 ft underground.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

How are isotopes of the same chemical element alike? how are they different?

Agust of wind blowing east pushes against a ball. when will the wind do work on the ball? when the ball moves to the east when the ball moves to the north when the ball stays in one place when the ball moves north or south