The answer is (4) synthesis. Synthesis reaction means that two or more reactants combine directly to one production. Substitution or single replacement means that one element of a compound is replaced by another element. Double replacement means that two ionic reactants exchange ions to form two new productions.
Answer:

Explanation:
The unbalanced nuclear equation is

Let's write X as a nuclear symbol.

The main point to remember in balancing nuclear equations is that the sums of the superscripts and of the subscripts must be the same on each side of the reaction arrow.
Then
235 = 4 + A , so A = 235 - 4 = 231, and
92 = 2 + Z , so Z = 92 - 2 = 90
And your nuclear equation becomes

Element 90 is thorium, so

Answer:

Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to figure out the required net ionic equation by firstly writing out the complete molecular equation between aspirin and sodium acetate:

Whereas acetic acid and sodium acetylsalicylate are formed. Now, we write the complete ionic equation whereby sodium acetate and sodium acetylsalicylate are ionized because they are salts yet neither aspirin nor acetic acid are ionized as they are weak acids:

Finally, for the net ionic equation we cancel out the sodium spectator ions to obtain:

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