Option 4 seems to be the one undergoing a chemical change because there is a formation gas from the bubbling that occurs. Chemical change is the change that results to the formation of a new substance. The other options given are examples of physical change.
Covalent substances have weaker intermolecular attractions.
D- It requires heat as a reactant
<span>The arrangement of the periodic table leads us to visualize certain trends among the atoms. The vertical columns ( basically their groups) of the periodic table and they are arranged such that all its elements have the same number of valence electrons. And all the elements within a certain group thus share similar properties and that's about it.</span>
Answer:
Autotrophs
Explanation:
They are responsible for the production of food. Root words "auto" for self and "troph" for food.