Answer: ₉₈²⁵³Cf
253 is a superscript to the left of the symbol, Cf, which represents the mass number, and 98 is a subscript to the left of the same symbol, which represents the atomic number.
Explanation:
1) The alpha decay equation shows that the isotope Fm - 257, whose nucleus has 100 protons and 157 neutrons, emitted an alpha particle (a nucleus with 2 protons and 2 neutrons).
2) Therefore:
i) the mass number decreased in 4, from 257 to 257 - 4 = 253.
2) the atomic number decreased in 2, from 100 to 100 - 2 = 98.
3) Hence the formed atom has atomic number 98, which is californium, Cf, and the isotope is californium - 253.
4) The item that completes the given alpha decay reaction is:
₉₈²⁵³ Cf.
5) The complete alfpha decay reaction is:
₁₀₀²⁵⁷ Fm → ₉₈²⁵³Cf + ₂⁴He
You can verify the mass balance:
257 = 253 + 4, and
100 = 98 + 2
Sodium has a lower ionization energy than magnesium describes why sodium reacts vigorously than magnesium chloride.
<h3>Why is sodium more reactive than magnesium?</h3>
- Sodium is more reactive than magnesium because it has the ability to easily lose electron, hence have lower ionization energy.
- Sodium belong to group one on the periodic table and they are called akali metal while magnesium belong to group two on the periodic table and they are called alkali Earth metal.
- Sodium and magnesium belong to the in the 3rd period. Iin the outermost energy level sodium has one electron but magnesium has 2 electrons. Therefore, there is more attraction abetween the nucleus and electrons in magnesium than that of sodium.
Therefore, sodium is more reactive than magnesium chloride because of lower ionization energy.
For more details on sodium reactivity, check the link below.
brainly.com/question/6837593
Answer:
Sunlight
Water
And carbon dioxide
Additional information :
6CO2 + 6H2O → C6H12O6 + 6O2