Question

Identify the element represented by each of the following symbols and give the number of protons and neutrons in each: (a) \(33^{7} X\), (b) \(\frac{127}{53} \mathrm{X}\), (c) \(\frac{152}{63} \mathrm{X}\) (d) \({ }_{83}^{209} \mathrm{X}\).

Short answer

(a) The element is nitrogen (N) with 7 protons and 26 neutrons. (b) The element is iodine (I) with 53 protons and 74 neutrons. (c) The element is europium (Eu) with 63 protons and 89 neutrons. (d) The element is bismuth (Bi) with 83 protons and 126 neutrons.

Step-by-step solution

(a) Identify the element and number of protons and neutrons for \(^{33}_7 X\)

First, we need to find out which element has the atomic number 7. Looking at the periodic table, we can see that the element with atomic number 7 is nitrogen (N). Now, let's find the number of neutrons: Neutrons = Mass number - Atomic number Neutrons = \(33 - 7 = 26\) Thus, the element is nitrogen (N), and it has 7 protons and 26 neutrons.

(b) Identify the element and number of protons and neutrons for \(\frac{127}{53} \mathrm{X}\)

Next, we need to find out which element has the atomic number 53. From the periodic table, the element with atomic number 53 is iodine (I). Now, let's find the number of neutrons: Neutrons = Mass number - Atomic number Neutrons = \(127 - 53 = 74\) The element is iodine (I), and it has 53 protons and 74 neutrons.

(c) Identify the element and number of protons and neutrons for \(\frac{152}{63} \mathrm{X}\)

Now, let's find the element with the atomic number 63. Looking at the periodic table, the element with atomic number 63 is europium (Eu). Let's find the number of neutrons: Neutrons = Mass number - Atomic number Neutrons = \(152 - 63 = 89\) The element is europium (Eu), and it has 63 protons and 89 neutrons.

(d) Identify the element and number of protons and neutrons for \(^{209}_{83} \mathrm{X}\)

Finally, we need to find out which element has the atomic number 83. From the periodic table, the element with atomic number 83 is bismuth (Bi). Now, let's find the number of neutrons: Neutrons = Mass number - Atomic number Neutrons = \(209 - 83 = 126\) The element is bismuth (Bi), and it has 83 protons and 126 neutrons.

Key concepts

Element Identification

Identifying an element involves looking at the atomic number, which represents the number of protons in an atom's nucleus. This atomic number is unique for each element and serves as its fingerprint on the periodic table. For example, the atomic number 7 corresponds to nitrogen (N), while 53 corresponds to iodine (I). When you know the atomic number, you can immediately identify an element using the periodic table.
It's important to remember:

• Atomic number = Number of protons
• Elements with different atomic numbers are different elements altogether

Understanding this concept is key to solving problems related to atomic structure.

Protons and Neutrons

Protons and neutrons are the subatomic particles found within the nucleus of an atom. Protons carry a positive charge, while neutrons are neutral. They play a crucial role in determining the characteristics of an atom. Each element's identity depends on the number of protons present in the nucleus.
To find the number of neutrons, subtract the atomic number from the mass number. For instance, if the atomic number is 83 and the mass number is 209, the neutrons are calculated as follows:
Neutrons = Mass number - Atomic number = 209 - 83 = 126.

• Protons define the element’s identity.
• Neutrons contribute to the atom’s mass but don't change the element.

Knowing the number of these particles helps in understanding isotopes—atoms with the same number of protons but different numbers of neutrons.

Mass Number and Atomic Number

The mass number and atomic number together tell a lot about an atom's structure. The atomic number is the count of protons and defines the element, as explained earlier. The mass number is the sum of protons and neutrons in the nucleus and approximately equals the atom's mass. For example, if an atom has a mass number of 152 and an atomic number of 63, it is europium (Eu) with 63 protons and 89 neutrons.
Here’s a quick summary of how these numbers work:

• Atomic number = Number of protons (and also electrons in a neutral atom)
• Mass number = Number of protons + neutrons

By understanding these numbers, you can calculate the composition of an atom and more deeply explore the properties of elements.