Question

1. collect data: set protons to 1 and neutrons to 0. below the graph, click save point. notice on the graph the stable isotopes are shown in blue and the radioactive isotopes in green.

add protons and neutrons and use the save point button to record data for the first seven elements. try to find all of the stable isotopes. (note: you can drag the point direction to any location on the graph.)
a. do the stable isotopes appear to fall on a line?

b. how many stable isotopes have equal numbers of protons and neutrons?

c. turn on show neutron:proton ratio. drag the blue line until it lines up with most of the blue points. approximately what n:p ratio do most stable isotopes have?

Explanation:

Step1: Analyze the data - general

By adding protons and neutrons and observing the graph for the first seven elements.

Step2: Answer part A

When observing the graph of stable isotopes (blue points), they generally appear to fall on a line as the neutron - proton relationship follows a certain pattern for stability. So the answer to A is yes.

Step3: Answer part B

For the first seven elements:

• Hydrogen (H): Protons = 1, neutrons = 0 (no equal protons and neutrons)
• Helium (He): Protons = 2, neutrons = 2 (1 such stable isotope)
• Lithium (Li): Stable isotopes have different neutron - proton ratios
• Beryllium (Be): Protons = 4, neutrons = 5 (no equal protons and neutrons)
• Boron (B): Stable isotopes have different neutron - proton ratios
• Carbon (C): Protons = 6, neutrons = 6 (1 such stable isotope)
• Nitrogen (N): Stable isotopes have different neutron - proton ratios

In total, 2 stable isotopes (He and C) have equal numbers of protons and neutrons.

Step4: Answer part C

For light elements (first seven elements), most stable isotopes have a neutron - proton (n:p) ratio close to 1.

Answer:

A. Yes
B. 2
C. 1