Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get
Therefore, the time required for decay is, 84 days.
Answer:
4 Co(s) + 3 O2(g) = 2 Co2O3(s)
Explanation:
<h3>
Answer:</h3>
3CaCl₂ + 2Na₃PO₄→ Ca₃(PO₄)₂ + 6NaCl
<h3>
Explanation:</h3>
We are given the Equation;
CaCl₂ + Na₃PO₄→ Ca₃(PO₄)₂ + NaCl
Assuming the question requires us to balance the equation;
- A balanced chemical equation is one that has equal number of atoms of each element on both sides of the equation.
- Balancing chemical equations ensures that they obey the law of conservation of mass in chemical equations.
- According to the law of conservation of mass in chemical equation, the mass of the reactants should always be equal to the mass of the products.
- Balancing chemical equations involves putting appropriate coefficients on the reactants and products.
In this case;
- To balance the equation we are going to put the coefficients 3, 2, 1, and 6.
- Therefore; the balanced equation will be;
3CaCl₂ + 2Na₃PO₄→ Ca₃(PO₄)₂ + 6NaCl
Answer:
C. The thermal energy of a substance.
Explanation:
Hope it helps.
