mely high temperatures and pressures to give the positively charged nuclei sufficient kinetic energy to overcome their mutual electrostatic repulsion B1\n- Explains that for a new scientific claim to be accepted, the experiment must undergo peer review and the results must be independently reproduced or replicated by other research groups B1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"scientific_scepticism","label":"Explain the scepticism","steps":[{"type":"text","order":1,"title":"Explain the physics","content":"Fusion joins two atomic nuclei. Both nuclei are positively charged, so they **repel** each other because of the electrostatic force.\n\nFor fusion to happen, nuclei need extremely high temperatures and pressures. This gives them enough kinetic energy to get close enough to overcome that repulsion. Therefore, a claim of fusion at only $450\\text{ }^{\\circ}\\text{C}$ was physically very surprising and gave scientists reason to doubt it.\n\nThis explanation earns the first mark.","highlights":[{"text":"nuclear fusion at a temperature of just $450\\text{ }^{\\circ}\\text{C}$","location":"specification"}]},{"type":"text","order":2,"title":"Require independent checks","content":"A single research group's result is not enough to establish a new scientific claim, especially one that conflicts with what is normally expected. Other scientists need to examine the method through **peer review** and independently reproduce or replicate the result.\n\nUntil independent groups obtained the same evidence, the wider community was right to remain sceptical. This earns the second mark.","highlights":[{"text":"before any independent validation","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:28:08.542Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"8946cd55-3a8b-40ef-9186-76156e8bc6d8","revisionId":"d339e516-5d3b-42ef-8c75-81dce348576c","questionNumber":null,"questionType":"LA","specification":"","difficulty":4,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"93009b30-f7eb-46db-aaba-caab4f8ff5b9","label":null,"content":"Explain the effects on human body cells of prolonged exposure to ionizing radiation, such as beta particles.","markscheme":"- States that radiation penetrates the body and ionizes molecules or atoms inside cells B1\n- States that this ionization damages or mutates DNA B1\n- States that this can lead to uncontrolled cell division / cancer OR can kill cells / cause tissue damage B1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"radiation_cell_damage","label":"Trace radiation damage","steps":[{"type":"text","order":2,"title":"State the first effect","content":"Ionising radiation can penetrate the body. Inside cells, it **ionises atoms or molecules**: it removes electrons from them, leaving charged particles.\n\nThis is the first marking point because it identifies the direct effect of the radiation on cell material.","highlights":[{"text":"ionizing radiation, such as beta particles","location":"specification"}]},{"type":"text","order":3,"title":"Describe DNA damage","content":"Ionisation can damage or mutate DNA in the cell. This earns the second mark because it links ionisation directly to genetic material.","highlights":[{"text":"effects on human body cells","location":"specification"},{"text":"ionizing radiation","location":"specification"}]},{"type":"text","order":4,"title":"Give a consequence","content":"Damaged DNA can cause a cell to divide uncontrollably, leading to cancer. Alternatively, the damage can kill cells and damage body tissue.\n\nState either consequence clearly to earn the final marking point.","highlights":[{"text":"prolonged exposure","location":"specification"}]}]}],"generatedAt":"2026-07-22T12:07:45.107Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options"

Radiation safety and nuclear energy

Question 15

Radiation safety and nuclear energy Questions

Radiation safety and nuclear energy

Question 15

Radiation safety and nuclear energy Questions