Answer:

Explanation:
Hello there!
In this case, since the radioactive reaction for the alpha emission of astatine-218 to bismith-214 involve the release of a helium atom as shown below:

Whereas the atomic number decreases by 2 and the mass number by 4 in agreement to the release of the Helium atom.
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1 Cal ---------- 4.184 J
? Cal ---------- 130.0 J
130.0 x 1 / 4.184 => 31.07 Cal
hope this helps!
Answer:
X has 9 Electrons, 9 Protons and 10 Neutrons
X is Fluorine
Explanation:
19 in X is Nucleon number
So, if you minus 19 by 9 down there (which is proton number) you'll get 10 (Neutron number).
Now, Proton = Electron. That's why Electron is 9 too. I figured that X is Fluorine bcuz it has 9 Electrons. If you venture around in the periodic table, fluorine is the ninth element innit.
hope this helps ya \(^o^)/
Sucrose is stored in dry and closed container, sealed properly.
Explanation:
- Sucrose is nothing but the table sugar which we use daily in our life.
- Sucrose is formed by the combination of fructose and glucose so, it called a disaccharide because two monosaccharides are converted to form sucrose.
- It is a hygroscopic substance. The hygroscopic substance is which is easily vulnerable to water absorption. They tend to absorb water if they are being exposed to humid places.
- Hence, it should be kept in a dry and close container, sealed properly.