Question

3
use a periodic table of the elements to answer these questions.

1. the following graphics represent the nuclei of atoms. using a periodic table of elements, fill in the table.

what the nucleus looks like	what is this element?	how many electrons does the neutral atom have?	what is the mass number?
(image of nucleus with p and n)
(image of nucleus with p)

1. look at a periodic table. the atomic mass of hydrogen is 1.00794. why is this number not rounded off to 1?

1. how many protons and neutrons are in the nucleus of each isotope?

a. hydrogen-2 (atomic number = 1)
b. scandium-45 (atomic number = 21)

Explanation:

Question 1 (Table Filling)

Row 1 (First Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 3, Neutrons (N) = 4. Atomic number = number of protons = 3. So the element is Lithium (Li).

Step2: Electrons in Neutral Atom

In a neutral atom, electrons = protons = 3.

Step3: Mass Number

Mass number = protons + neutrons = \(3 + 4 = 7\).

Row 2 (Second Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 5, Neutrons (N) = 6. Atomic number = 5. Element is Boron (B).

Step2: Electrons in Neutral Atom

Electrons = protons = 5.

Step3: Mass Number

Mass number = \(5 + 6 = 11\).

Row 3 (Third Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 1, Neutrons (N) = 0. Atomic number = 1. Element is Hydrogen (H).
##[LLM SSE On Failure]

Answer:

Question 1 (Table Filling)

Row 1 (First Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 3, Neutrons (N) = 4. Atomic number = number of protons = 3. So the element is Lithium (Li).

Step2: Electrons in Neutral Atom

In a neutral atom, electrons = protons = 3.

Step3: Mass Number

Mass number = protons + neutrons = \(3 + 4 = 7\).

Row 2 (Second Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 5, Neutrons (N) = 6. Atomic number = 5. Element is Boron (B).

Step2: Electrons in Neutral Atom

Electrons = protons = 5.

Step3: Mass Number

Mass number = \(5 + 6 = 11\).

Row 3 (Third Nucleus)

Step1: Count Protons and Neutrons

Protons (P) = 1, Neutrons (N) = 0. Atomic number = 1. Element is Hydrogen (H).
##[LLM SSE On Failure]