These images of the santa cruz river in arizona were taken in 1942 and 1989. during the period between these years, the growth of vegetation declined substantially in the area. what are the two most likely explanations for this change in vegetation

The roots could no longer access depleted groundwater.

The topsoil in the area eroded.

The roots could no longer access depleted groundwater.

The topsoil in the area eroded.

THIS IS CORRECT

vanderwaal's forces of attraction are the electrostatic intermolecular forces that exist in a molecule due to the temporary or permanent dipoles that are developed in a molecule. in , the major intermolecular forces are dipole-dipole interactions as the molecule is polar (bent structure). so the vanderwaal's forces of interaction in between molecules are the permanent dipole-dipole interactions that develop due to the dipole that exists in between the polar h - s bond. the positively charged hydrogen atom is attracted towards the negative end of the dipole that is sulfur of the adjacent molecule. therefore, these forces of attraction are relatively stronger than that of london dispersion forces that exist in non polar molecules.

the major pests we deal with are insects, weeds and fungal diseases. a pesticide is a product, whether organic or chemical, used to kill the target pest. there are other techniques gardeners should use that can prevent the severe infestations that make the use of pesticides necessary