Lithium is an element that has an electronic configuration of 2,1. So when forming bonds, it tries to release one of its electrons in the last shell to reach the octet state. Normally when atoms release electrons they get positive charge since the number of protons which bear positive charge, is higher than number of electrons which bear negative charge. So when reaching its octet state, lithium gains positive charge!
Hope this helps! Tbh am not good at explaining. If u have any doubts, ask me!
Why does a patch of garbage in the ocean effect humans on land
A producer gets it's matter from it's surroundings. E.g a plant will get minerals and water from the ground through it's roots for photosynthesis.
Plants can also produce food by using the sun's light for photolysis of the water molecules. (Basically splitting the H20 into Hydrogen and O2 (oxygen gas). They release oxygen back into the air and combine the Hydrogen ion with carbon dioxide that they obtained from the air to create sugar (glucose) which is basically chemical food for the plants. This is the summed up process of photosynthesis.