Answer:
d. Radon-222
Explanation:
²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He
Alpha particle is a helium nucleus with mass number 4 and atomic number 2. According to the law of conversation of mass, the sum of the mass number and atomic number must be equal on both side of the reaction.
Since the mass number of Ra is 226 and that of He is 4. The mass number of the unknown element must be 226 - 4 = 222.
Since the atomic number of Ra is 88 and that of He is 2. The atomic number of the unknown element must be 88 - 2 = 86.
Now looking in the periodic table Radon is the only element with atomic number 86.
7 A lead
B Gold
Csilver
8 Afeathrr
B water
C silver
Answer:
Heat going into a substance changes it from a solid to a liquid or a liquid to a gas. Removing heat from a substance changes a gas to a liquid or a liquid to a solid.
Liquid → Gas:
VaporizationGas → Liquid:
CondensationSolid → Liquid:
Melting or fusion
Solid → Gas: Sublimation
Explanation:
Answer:
The grey squirrel.
Explanation:
This is your answer because the white one would have a harder time to blend in with the tree's and the environment, whilst the grey one is better suited for its environment better due to the fact that it can blend in with the trees, and hide better.
Proton = +1
neutron = 0
electron = -1
