a student is constructing the model shown to present information about three atoms.\n3 li lithium 6.94\n4 be…

a student is constructing the model shown to present information about three atoms.\n3 li lithium 6.94\n4 be beryllium 9.01\n5 b boron 10.81\nusing the beryllium (be) model as a reference, which set of steps should the student follow to correctly construct the model of a boron atom?\n1. add two more black spheres to the nucleus.\n2. keep the number of gray spheres in the nucleus the same.\n3. add two more dots to the outer electron cloud.\n1. add another black sphere to the nucleus.\n2. add another gray sphere to the nucleus.\n3. add another dot to the electron cloud.\n1. keep the number of black spheres in the nucleus the same.\n2. add two more gray spheres to the nucleus.\n3. keep the number of dots in the electron cloud the same.\n1. add another black sphere to the nucleus.\n2. add two more gray spheres to the nucleus.\n3. keep the number of dots in the electron cloud the same.

a student is constructing the model shown to present information about three atoms.\n3 li lithium 6.94\n4 be beryllium 9.01\n5 b boron 10.81\nusing the beryllium (be) model as a reference, which set of steps should the student follow to correctly construct the model of a boron atom?\n1. add two more black spheres to the nucleus.\n2. keep the number of gray spheres in the nucleus the same.\n3. add two more dots to the outer electron cloud.\n1. add another black sphere to the nucleus.\n2. add another gray sphere to the nucleus.\n3. add another dot to the electron cloud.\n1. keep the number of black spheres in the nucleus the same.\n2. add two more gray spheres to the nucleus.\n3. keep the number of dots in the electron cloud the same.\n1. add another black sphere to the nucleus.\n2. add two more gray spheres to the nucleus.\n3. keep the number of dots in the electron cloud the same.

Answer

Explanation:

Step1: Recall atomic structure basics

Atomic number increases by 1 from Be (4) to B (5). Protons (black spheres) determine atomic number. Neutrons (gray spheres) can vary. Electrons (dots) equal protons in neutral atoms.

Step2: Analyze each option

  • Option a: Adding 2 black spheres changes atomic number too much.
  • Option b: Adding 1 black sphere (proton) increases atomic number by 1, adding 1 gray sphere (neutron) is fine, and adding 1 electron as atomic number increased by 1 is correct for a neutral atom.
  • Option c: Keeping proton number same doesn't change atomic number to that of boron.
  • Option d: Keeping electron number same while increasing protons and neutrons doesn't account for charge - neutrality as atomic number is changing.

Answer:

B. 1. Add another black sphere to the nucleus. 2. Add another gray sphere to the nucleus. 3. Add another dot to the electron cloud.