The simple trick which one can consider in such problem where it is asked for positron emission is :
<span>When the atomic number goes DOWN by one and mass number remains unchanged, then a positron is emitted.
</span>
<span>a. </span>

<span>
Here the atomic number decreases by one.
Similarly, options b and d are eliminated.
Option c is also not the answer.
For c, Count the atomic number on left side and compare it with right side. You will see it is 9 on left and 8 on right. Atomic no. did go down by 1. But the atomic mass is changed as well.
</span>
atoms are made of 3 types of sub atomic particles; neutrons, protons and electrons
atomic number is the number of protons which is characteristic for the element. Atoms of the same element have the same number of protons.
mass number is the sum of the neutrons and protons.
Isotopes are atoms of the same element with different mass numbers. since they are the same element number of protons are the same but number of neutrons vary.
therefore 2 isotopes are of the same element so they have the same number of protons.
Question: Baking a Cake Without Flour.
Hypothesis: I think that when I remove the flour from the standard cake recipe, I'll end up with a flat but tasty cake.
Procedure: I baked two cakes during my experiment. For my control, I baked a cake following a normal recipe. I used the Double Fudge Cake recipe on page 292 of the Betty Crocker Cookbook. For my experimental cake, I followed the same recipe but left out the flour. I first obtained a 2-quart mixing bowl.
Results: My control cake, which I cooked for 25 minutes, measured 4 cm high. Eight out of ten tasters that I picked at random from the class found it to be an acceptable dessert. After 25 minutes of baking, my experimental cake was 1.5 cm high and all ten tasters refused to eat it because it was burnt to a crisp.
What did I learn?/Conclusion: Since the experimental cake burned, my results did not support my hypothesis. I think that the cake burned because it had less mass, but cooked for the same amount of time. I propose that the baking time be shortened in subsequent trials.
-
I hope this helped :))
Answer: In the Western United States and Canada, open range is rangeland where cattle roam freely regardless of land ownership. ... Land in open range that is designated as part of a "herd district" reverses liabilities, requiring an animal's owner to fence it in or otherwise keep it on the person's own property.
Explanation: Mark me as brainliest