4. unstable and spontaneously emits alpha particles
Explanation:
Nuclei of uranium-28 atoms are typically unstable and spontaneously emits alpha particles.
Unstable nuclei are nuclei whose neutron/proton ratio is different from its stability ratio.
- Most nuclei heavier than Bi-209 are naturally radioactive.
- Nuclei of U-238 is unstable and it spontaneously disintegrates.
²³⁸₉₂U → ²³⁴₉₀Th + ⁴₂He
- The uranium decays to produce thorium nuclei with the emission of alpha particles, He.
Learn more:
Nuclear decay brainly.com/question/10094982
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Due to the tilt of the earth
Answer:
Explanation:
photosynthesis
the given chemical reaction is photosynthesis.
During photosynthesis carbon dioxide absorbed by plants reacts with water in presence of sunlight to give glucose and oxygen.
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<span>the change in carbon dioxide levels in the atmosphere
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hope that's right and hope i helped