If a metal changes color overtime from exposure to air what has likely occurred? ?
• a reversible change
• a chemical change
• a physical change
• a change of state

Plz plz plz quick! 49 points for whoever which of the following statements about greenhouse effect is true? *life on earth is suffering because of greenhouse effect *the greenhouse effect is caused by human activity *all greenhouse gases are harmful *life on earth would not exist without the greenhouse effect

If you have a difficult time knowing where your hand is without looking at it you may be having a problem with your what ?

Diffusion and osmosis are forms of passive transport