We have to get the stable atom formed after positron emission from Terbium-147.
The stable atom is (D) ₆₄Gd¹⁴⁷.
Positron is radioactive decay. Positron is a type of beta particle β⁺.
Positron emission decreases proton number relative to neutron number, positron decay results in nuclear transmutation, changing an atom of one chemical element with an atomic number that is less by one.
Terbium on positron emission produces Gadolinium with one atomic number less than Terbium. So, the positron emission reaction is as shown below:
Tb¹⁴⁷→ ₆₄Gd¹⁴⁷ + ₁e⁰
I believe the answer is A. <span>wavelength and frequency. </span>
Answer:- Mass of the alloy is 2.8 kg.
Solution:- Mass of Cr in the alloy is 325 g and mass of Fe in the alloy is 2.5 kg. Mass of alloy would be the sum of masses of constituent metals.
Masses of the metals are not in the same units. So, we need to make the units equal. The want answer in kg so let's convert mass of Cr from g to kg.
Since, 1000 g = 1 kg
So, 
= 0.325 kg
Mass of alloy = mass of Cr + mass of Fe
mass of alloy = 0.325 kg + 2.5 kg = 2.825 kg
If we consider significant figures then as per the rules, the answer should not have more than one decimal place.
So, 2.825 kg is round off to 2.8 kg and hence the mass of the alloy is 2.8 kg.
Answer:
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Explanation:
We have the reactants as calcium chloride and potassium carbonate. Recall that we are expecting that the reaction will yield a precipitate. We must keep that in mind as we seek to write its balanced chemical reaction equation.
So we now have;
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Recall that the rule of balancing chemical reaction equation states that the number of atoms of each element on the right side of the reaction equation must be the same as the number of atoms of the same element on the left hand side of the reaction equation.
