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.
The initial concentration of the unknown acid is 0.1900 M.
Explanation:
Titration is a chemical method of analysis to know the concentration and volume of the unknown chemical or analyte.
The formula for the titration is:
Macid x Vacid = Mbase x V base
The volume must be in litres. The volume is given in ml it should be divided with 1000 to obtain values in litre.
Data given are:
volume of acid= 10 ml 0.01 L
Molarity of the acid = ?
volume of the NaOH or base = 15.4 ml or 0.0154 L (equivalence point of the base)
molarity of the base = 0.1234 M
Applying the formula and putting the values, we get
Macid x 0.01 = 0.1234 x 0.0154
Macid = 0.1900 M
The weak acid is having molarity of 0.1900 M against the strong base with molarity of 0.1234M.
What are some of the body's internal defenses. The skin helps protect stuff to!
Answer:
10grams
Explanation:
So it weighs 236 grams added with 25 grams. So it now weighs 261 grams so 10 grams of sugar remains in it.
