An atom has 9 electrons and 9 protons at the start. If it loses 2 electrons, the net charge on the atom will be __. If the atom instead gains 4 electrons, the net charge will be__.

At a temperature of 393 k, the temperature of a sample of nitrogen is 1.07 atm what will the pressure be at a temperature of 478 k

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world