When u-238 transmutates into th-234, this represents?

Answer is: alpha decay.

Nuclear reaction: ²³⁸U → ²³⁴Th + α (alpha particle).
Alpha particle is nucleus of a helium-4 atom, which is made of two protons and two neutrons.
Alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.

3 (die)4 (slips)6 (spinner)5 (ace)

Step-by-step explanation:

Josie rolls a six-sided die 18 times. What is the estimated number of times she rolls a two? 3 = (1/6)(18)

Slips of paper are numbered 1 through 10. If one slip is drawn and replaced 40 times, how many times should the slip with number 10 appear? 4 = (1/10)(40)

A spinner consists of 10 equal- sized spaces: 2 red, 3 black, and 5 white. If the spinner is spun 30 times, how many times should it land on a red space? 6 = (2/10)(30)

A card is picked from a standard deck of playing cards 65 times and replaced each time. About how many times would the card drawn be an ace? 5 = (4/52)(65)

The probability of a given event is the number of ways it can occur divided by the number of possibilities. For example, a 2 is one of 6 numbers on a die, so we expect its probability of showing up to be 1/6. The expected number of times it will show up in 18 rolls of the die is (1/6)(18) = 3.