Which of the following statements is false? which of the following statements is false?
a. mixtures may be composed of two or more elements, two or more compounds, or a combination of both.
b. a mixture may be either homogeneous or heterogeneous.
c. matter may be a pure substance or it may be a mixture.
d. a pure substance may either be an element or a compound.
e. all of the above statements are true

option A) Mixtures may be composed of two or more elements, two or more compounds, or a combination of both.

Explanation:

A mixture is a combination of two or more substances mixed together and can be separated by physical methods.

A combination of two elements or compounds will yield chemical compounds NOT a mixture.

Thus, option A is false statement

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.