How many protons does an Aluminum atom with 13 electrons have? A. 15 B. 10 C. 13 D. 16 2. An atom has a mass number of 23 and an atomic number of 11. How many electrons are present in that atom? A. 11 B. 12 C. 23 D. 34 3. How many protons does an atom with 34 electrons have? A. 35 B. 36 C. 33 D. 34 4. How many protons does a hydrogen atom have? A. 0 B. 1 C. 2 D. 3 5. What is the atomic number of an atom that contains 28 protons, 28 electrons, and 34 neutrons? A. 28 B. 56 C. 62 D. 90
The Correct Answer and Explanation is:
Here are the answers and explanations for each of the questions:
- How many protons does an Aluminum atom with 13 electrons have?
Answer: C. 13
Explanation: The number of protons in an atom is equal to its atomic number. Aluminum (Al) has an atomic number of 13, which means it has 13 protons. The number of electrons in a neutral atom is also 13, which matches the number of protons, maintaining electrical neutrality. - An atom has a mass number of 23 and an atomic number of 11. How many electrons are present in that atom?
Answer: A. 11
Explanation: The atomic number of an atom indicates the number of protons and, in a neutral atom, also the number of electrons. The mass number (23) is the sum of protons and neutrons, but the number of electrons is determined by the atomic number. Therefore, since the atomic number is 11, the atom has 11 electrons. - How many protons does an atom with 34 electrons have?
Answer: D. 34
Explanation: In a neutral atom, the number of protons is equal to the number of electrons. If the atom has 34 electrons, it must also have 34 protons. The element with 34 protons is Selenium (Se). - How many protons does a hydrogen atom have?
Answer: B. 1
Explanation: Hydrogen is the simplest element with only one proton. Its atomic number is 1, indicating that it has 1 proton in its nucleus. In its most common isotope, hydrogen also has 1 electron, making it electrically neutral. - What is the atomic number of an atom that contains 28 protons, 28 electrons, and 34 neutrons?
Answer: A. 28
Explanation: The atomic number of an element is defined by the number of protons in its nucleus. In this case, the atom has 28 protons, so its atomic number is 28. This atom is nickel (Ni). The number of neutrons (34) is unrelated to the atomic number and instead helps define the isotope of the element.
