I am a transition metal with 25 electrons.
Answer Manganese (Mn)
A neutral atom has as many electrons as protons, so the atomic number is 25. Element 25 is manganese, a transition metal in group 7.
Element riddle solver
Which element am I? Solve element riddles step by step
Type a chemistry riddle such as “I am a transition metal with 25 electrons”, or set the clues by hand. The solver narrows the 118 elements one clue at a time and explains every step.
Answer
Clues found
- Electrons: Technetium + 9
Tellurium (Te), element 52
How it was solved
- Electrons: Technetium + 9. Elements that still fit: 1.
- Technetium is element 43, and 43 + 9 = 52.
Worked examples
Riddles of the kind set in chemistry homework, each solved from the periodic table.
I am a transition metal in group 10 with 31 neutrons.
Answer Nickel (Ni)
Group 10 holds nickel, palladium, platinum and darmstadtium. With the classroom shortcut, rounded atomic mass minus atomic number, nickel gives 59 − 28 = 31; its most common isotope, nickel-58, has 30.
This element has 2 fewer protons than tennessine (Ts).
Answer Moscovium (Mc)
Tennessine is element 117, so the answer has 117 − 2 = 115 protons. Element 115 is moscovium (Mc).
This element has 9 more electrons than technetium (Tc).
Answer Tellurium (Te)
Technetium has 43 electrons, and 43 + 9 = 52. Element 52 is tellurium.
This element is directly below the element that has 34 protons in its nucleus.
Answer Tellurium (Te)
The element with 34 protons is selenium, in group 16 and period 4. Directly below it, in period 5, is tellurium.
This element has 113 electrons surrounding its nucleus.
Answer Nihonium (Nh)
A neutral atom has as many electrons as protons, so this is element 113, nihonium, a synthetic element named after Japan.
I am a liquid metal with 80 electrons.
Answer Mercury (Hg)
80 electrons means atomic number 80, mercury. It melts at −38.8 °C, so it is a liquid at room temperature.
What element has 34 protons and 45 neutrons?
Answer Selenium (Se)
34 protons makes it selenium. Its atomic mass, 78.97, rounds to 79, and 79 − 34 = 45; its most common isotope, selenium-80, has 46.
Which element is classified as a noble gas? O, N, Cl, Xe
Answer Xenon (Xe)
Xenon is the only noble gas in the list: oxygen and nitrogen are nonmetals and chlorine is a halogen.
Which element in the transition metal family has the largest atomic mass?
Answer Copernicium (Cn)
Copernicium, element 112, has the largest listed mass (285), but it is made only in laboratories. Of the transition metals found in nature, mercury is the heaviest, at 200.59.
I am a halogen in period 3.
Answer Chlorine (Cl)
The halogens are group 17, and group 17 in period 3 is chlorine.
I am an alkali metal in period 4.
Answer Potassium (K)
The alkali metals are group 1 without hydrogen, and group 1 in period 4 is potassium.
What element has 26 protons and 30 neutrons?
Answer Iron (Fe)
26 protons makes it iron. Its atomic mass, 55.85, rounds to 56, and 56 − 26 = 30, which is also the neutron count of its most common isotope, iron-56.
I am directly above silicon in the periodic table.
Answer Carbon (C)
Silicon sits in group 14, period 3. Directly above it, in period 2, is carbon.
Two ways to count neutrons
Homework riddles usually take the atomic mass from the periodic table, round it to a whole number and subtract the atomic number. For nickel that gives 59 − 28 = 31.
A real nickel atom most often has 30 neutrons, because its most common isotope is nickel-58. The solver accepts either reading and says which one the riddle used. Nickel (Ni)
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