Which statement about atomic structure is incorrect?
a) protons are located in the nucleus.
b) protons and electrons have the same mass.
c) protons and electrons have opposite charges.
d) neutral atoms contain the same number of protons and electrons.

The correct answer is B proton and electron have same mass .

Explanation:

The mass of a proton is 1.67×10∧-27 kg whereas the mass of an electron is 9.1×10∧-31 kg.

    From this point of view it can be stated that a proton is more heavier than an electron.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.