Half life is the time taken by a radioactive isotope to decay by half its original mass.
The original mass is 200 g
Time taken is 60 hours
Final mass is 25 g
Therefore;
Final mass = Original mass × (1/2)^n; where n is the number of half lives.
25 = 200 (1/2)^n
1/8 = (1/2)^n
n = 3
Three half lives = 60 hours
1 half lives = 20 hours
Therefore; the half life of the radioactive nucleus is 20 hours
Answer:
•Li2S is at a low melting point
•NCL3 is a covalent bond
Explanation:
Just some notes to help you:))
Covalent Bonds: A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons
Answer:
- The name for the potassium oxide's structure is ionic.
Properties:
- High melting point.
- Soluble in water.
Explanation:
- The ionic structure it is formed by a cation (atom with positive charge) and an anion (atom with negative charge). In this case, potassium is the cation and the oxigen is the anion.
- Since potassium oxide is an ionic compound, it has a high melting point, because of the strong bonds. Also, it is soluble in polar solvents, like water, because its ions generate polarity in the molecule.
It would be C
2 kg x 1000 g/kg x 1mol/18.02 x 6.03 kj/mol = 669kj
Answer:
An element
Explanation:
Elements are not able to be separated, but everything else can, whether that be physically or chemically.
