Answer: With atomic number 20, calcium atoms have 20 positive protons, and the ion has only 18 electrons, which means the net charge is +2. Calcium ions are essential for muscle contractions, nerve impulses, and bone maintenance.
:
A technician mixes 80 ml of a 5% solution with 10 ml of water. the final percentage strength of the solution prepared is 40 %.
given that :
8 ml of a 5 % solution mix with 10 ml . that means the 80 mL of 5 % solution is diluted with water of 10 mL
therefore, 80 × 5 = 10 × x %
x % = 40 %
Therefore, the final percentage strength of the solution is 40 %
Thus, A technician mixes 80 ml of a 5% solution with 10 ml of water. the final percentage strength of the solution prepared is 40 %.
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The direction of heat flow is increased which means blocks temperature is higher and hotter than it was before
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Answer:</h3>
Lead-205 (Pb-205)
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Explanation:</h3>
<u>We are given;</u>
We are supposed to identify its product after an alpha decay;
- Polonium-209 has a mass number of 209 and an atomic number of 84.
- When an element undergoes an alpha decay, the mass number decreases by 4 while the atomic number decreases by 2.
- Therefore, when Po-209 undergoes alpha decay it results to the formation of a product with a mass number of 205 and atomic number of 82.
- The product from this decay is Pb-205, because Pb-205 has a mass number of 205 and atomic number 82.
- The equation for the decay is;
²⁰⁹₈₄Po → ²⁰⁵₈₂Pb + ⁴₂He
- Note; An alpha particle is represented by a helium nucleus, ⁴₂He.
Answer:Respuesta. El peso molecular de NaCl es 58gr que equivale a 1 mol. g? hay 0,5mol queda 29gr
Explanation:
