Which statement is always true when nuclear fusion occurs?
The combined number of protons and neutrons remains constant. The combined number of protons and neutrons remains constant. The total number of protons and neutrons in each nucleus remains constant. The total number of protons and neutrons in each nucleus remains constant. The number of protons in the resulting nucleus is less than in each starting nucleus. The number of protons in the resulting nucleus is less than in each starting nucleus. The number of protons in the resulting nucleus is double that of a starting nucleus.
The total number of protons and neutrons in each nucleus remains constant.
The statement that is always true when nuclear fusion occurs is: "The combined number of protons and neutrons remains constant."
To determine which statement is always true when nuclear fusion occurs, we need to understand the process of nuclear fusion.
Nuclear fusion is a reaction in which two or more atomic nuclei come together to form a single, larger nucleus. During this process, there can be changes in the number of protons and neutrons in the resulting nucleus.
Let's analyze each statement:
1. The combined number of protons and neutrons remains constant.
This statement is incorrect. In nuclear fusion, the combined number of protons and neutrons in the resulting nucleus can vary depending on the specific reaction.
2. The total number of protons and neutrons in each nucleus remains constant.
This statement is incorrect. The total number of protons and neutrons in each nucleus involved in the fusion reaction does not remain constant.
3. The number of protons in the resulting nucleus is less than in each starting nucleus.
This statement can be true in some fusion reactions. For example, in the process of nuclear fusion that occurs in the Sun, four hydrogen nuclei (each consisting of one proton) combine to form one helium nucleus (containing two protons). In this case, the number of protons in the resulting nucleus is indeed less than in each starting nucleus.
4. The number of protons in the resulting nucleus is double that of a starting nucleus.
This statement is incorrect. The number of protons in the resulting nucleus after fusion reactions can vary, but it is not always double that of a starting nucleus.
Based on the analysis, the statement "The number of protons in the resulting nucleus is less than in each starting nucleus" is the one that is always true when nuclear fusion occurs.
Use the equation to answer the question. 21H+ 21H→ 42H+energy Which statement best describes the mass numbers of the atoms in the reaction?
There is one atom with a mass number of 1. There is one atom with a mass number of 1. There is one atom with a mass number of 2. There is one atom with a mass number of 2. There are two atoms with mass numbers of 2. There are two atoms with mass numbers of 2. There are two atoms with mass numbers of 1.
The correct statement that best describes the mass numbers of the atoms in the reaction 21H + 21H → 42H + energy is: "There are two atoms with mass numbers of 1."
In the reaction, two hydrogen-1 (H-1) atoms combine to form one helium-2 (He-2) atom. Hydrogen-1 has a mass number of 1 (1 proton and 0 neutrons), and helium-2 has a mass number of 2 (2 protons and 2 neutrons).
Which fact is true during a fission chain reaction?
The total number of protons will increase over time. The total number of protons will increase over time. The number of freely-moving neutrons decreases over time. The number of freely-moving neutrons decreases over time. The number of freely-moving neutrons increases over time. The number of freely-moving neutrons increases over time. The total number of protons will decrease over time.
The true fact during a fission chain reaction is: "The number of freely-moving neutrons increases over time."
A neutron strikes an atom of uranium-235 to start a fission reaction. A student expresses this situation as 01n+235 92U . Which statement describes why the expression is incorrect?
The atomic number for uranium-235 is in the wrong location. The atomic number for uranium-235 is in the wrong location. The mass number for uranium-235 is in the wrong location. The mass number for uranium-235 is in the wrong location. A neutron should be expressed as 10n , not 01n . A neutron should be expressed as 0 to the 1th power n, not 1 to the 0 power n. A neutron should be expressed as 11H , not 01n .
The statement "The mass number for uranium-235 is in the wrong location" accurately describes why the expression is incorrect.
The correct expression for a neutron is "1n", not "01n". The "0" in "01n" suggests that the neutron has no mass, which is incorrect. The correct notation for a neutron should indicate a mass number of 1 and an atomic number of 0, resulting in "1n". Therefore, the incorrect location of the mass number for uranium-235 is the reason why the expression is incorrect.