<span>From the above given choices :
melting is an endothermic process</span>
Answer:

Explanation:
Your unbalanced nuclear equation is:

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
84 = x + 2, so x = 84 - 2 = 82
210 = y + 4, so y = 210 - 4 = 206
Element 82 is lead, so the nuclear equation becomes

Answer:
100ml of a stock 50% KNO3 solutions are needed to prepare 250ml of a 20% KNO3 solution.
Explanation:
In the given question it is mentioned that
S1=50%
V2=250ml
S2= 20%
We all know that
V1S1=V2S2
∴V1= V2×S2÷S1
∴V1= V2S2×1/S1
∴V1= 250×20÷50
∴V1= 100ml
Answer:
A.
Explanation:
You should NEVER eat or drink anything in a lab area. You never know what chemicals or gases are in the lab, and they can harm you.
Wearing a drawstring hoodie won't protect you from chemicals.
Don't wait to clean up chemicals, immediately get a teacher and clean it up (follow the teachers instructions). You never know what has spilled, and if it is harmful or not, or if there is a certain procedure to clean it up.
Don't change the equipment in the middle of an experiment. This can tamper with your results, and depending on what you are working with, this can be dangerous.
Answer:
Cl^-<NO3^-<H2O<F^-<CN^-
Explanation:
When we talk about base strength we are referring to how easily a chemical specie accepts protons.
The greater the ability of a specie to accept H^+, the greater its base strength.
The order of increasing base strengths of the species listed are shown in the answer above.