Question 34 Answer and Explanation _ACT 1996 Form ST1 Science Section

Passage VI

An atom has a nucleus, which consists of protons (positively charged particles) and neutrons (uncharged particles), surrounded by one or more electrons (negatively charged particles) which move in orbits (see Figure 1).

Table 1 contains data for several neutral and charged atoms containing only one electron. Table 1 includes the number of protons (Z); the identification of the initial orbit (n); the radius of the orbit (r); the energy (l, in electron volts, or eV) to remove an electron from the atom; and the energy (E) of a photon emitted when an electron falls from its initial orbit to the orbit where n = 1.

34. The hypothesis that for a given value of n, r decreases as net positive charge increases, is supported by the data for:

F. H and He⁺ only.

G. H and Li⁺² only.

H. H, He⁺, and Li⁺² only.

J. H, He⁺, Li⁺², and Be⁺³.

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

Look at table 1, when n=4, from H to He⁺, then to Li⁺², and Be⁺³, r gradually decreases, while the positive charge increases gradually