Answer:
19656J
Explanation:
Step 1:
Data obtained from the question.
Mass (M) = 78g
Initial temperature (T1) = 20°C
Final temperature (T2) = 80°C
Change in temperature (ΔT) = T2 – T1 =
80°C – 20°C = 60°C
Specific heat capacity (C) = 4.2J/g°C
Heat (Q) =...?
Step 2:
Determination of the heat required for the reaction.
Q = MCΔT
Q = 78 x 4.2 x 60
Q = 19656J
Therefore, 19656J of heat is required.
Answer:
Element X with atomic number 10 and atomic mass 21
Element Z with atomic number 10 and atomic mass 22
Explanation:
Isotopy is the existence of two or more atoms of the same element having the same atomic number but different mass numbers due to the differences in the number of neutrons in their various nuclei.
- Isotopes of an element have the same electronic configuration.
- They share the same chemical properties
- They only differ in their masses.
So, Element X and Z with atomic number 10 which is their number of electrons are isotopes. Their mass number, 21 and 22 differs.
I believe c is the right answer.
Answer:
c- dry cells can not be recharged
