Which element has the symbol K?
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This free periodic table quiz has 15 questions written by the StudyPDF team: element symbols and names, reading groups and periods, metals and metalloids, and the main trends. Answer all 15, then check your score and read the explanation for every question. It stays at the level of a first chemistry course.
All 15 questions at a glance
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1.Which element has the symbol K?
- A. Krypton
- B. Potassium
- C. Calcium
- D. Phosphorus
Answer: B. Potassium
K comes from kalium, an older name for potassium. Krypton is Kr, calcium is Ca and phosphorus is P. Symbols that do not match the English name usually come from an older Latin or German name, so they are worth learning as a set.
2.Which element has atomic number 6?
- A. Boron
- B. Nitrogen
- C. Carbon
- D. Oxygen
Answer: C. Carbon
The atomic number is the number of protons, and it is what the table is ordered by. Count along period 2: lithium is 3, beryllium 4, boron 5 and carbon 6. Nitrogen is 7 and oxygen is 8.
3.Complete the sentence.
A symbol starts with a capital letter and any second letter is lowercase, so Co is the element _____, while CO is the compound _____.
Options for blank 1: cobalt, copper, carbon, chlorine
Options for blank 2: carbon monoxide, cobalt oxide, carbon dioxide, copper oxide
Answer: cobalt, carbon monoxide
Co is one element, cobalt. CO is a carbon atom joined to an oxygen atom, which is carbon monoxide. Carbon dioxide is CO2, and copper is Cu. The capital letter is what tells you where one symbol ends and the next begins.
4.An element sits in period 3 and group 17. Which element is it?
- A. Fluorine
- B. Bromine
- C. Argon
- D. Chlorine
Answer: D. Chlorine
Period 3 is the third row, which runs from sodium to argon, and group 17 is the halogen column. They meet at chlorine. Fluorine is in group 17 but period 2, bromine is group 17 but period 4, and argon is period 3 but group 18.
5.Which of these elements are halogens? Select all that apply.
Select all that apply.
- A. Fluorine
- B. Chlorine
- C. Neon
- D. Bromine
- E. Sodium
Answer: A. Fluorine, B. Chlorine, D. Bromine
The halogens are group 17: fluorine, chlorine, bromine, iodine and astatine. Neon is a noble gas in group 18, and sodium is an alkali metal in group 1. The halogen names all end in -ine, which is a handy memory hook.
6.Lithium, sodium and potassium react in similar ways. What do their atoms have in common?
- A. One valence electron each
- B. The same number of protons
- C. The same number of electron shells
- D. The same atomic mass
Answer: A. One valence electron each
They are all in group 1, so each atom has one electron in its outer shell, and that electron is easy to lose. Protons, shells and mass all differ: each step down the group adds a shell.
7.Complete the sentence.
Mendeleev arranged his 1869 table mostly by increasing atomic _____. The modern table is arranged by increasing atomic _____.
Options for blank 1: number, mass, radius, charge
Options for blank 2: mass, number, volume, density
Answer: mass, number
Mendeleev ordered the elements mostly by atomic mass and left gaps for elements not yet found. Later work showed that the number of protons, the atomic number, is the better order. A few pairs, such as tellurium and iodine, sit in the opposite order if you go by mass.
8.How many elements are in period 1?
- A. 1
- B. 2
- C. 8
- D. 18
Answer: B. 2
Period 1 holds only hydrogen and helium, because the first electron shell fits just 2 electrons. Periods 2 and 3 hold 8 elements each, and the later periods are longer.
9.Which property is typical of metals?
- A. They conduct electricity well
- B. They are brittle when solid
- C. They are usually gases at room temperature
- D. They tend to gain electrons
Answer: A. They conduct electricity well
Metals are good conductors of heat and electricity, are usually shiny and can be hammered or drawn into wire. Brittle solids, gases and elements that tend to gain electrons describe nonmetals. Most metals are solid at room temperature, with mercury the usual exception.
10.Which element and symbol pairs are correct? Select all that apply.
Select all that apply.
- A. Gold: Au
- B. Silver: Si
- C. Lead: Pb
- D. Tin: Ti
- E. Mercury: Hg
Answer: A. Gold: Au, C. Lead: Pb, E. Mercury: Hg
Gold is Au (aurum), lead is Pb (plumbum) and mercury is Hg (hydrargyrum). Silver is Ag (argentum), and Si is silicon. Tin is Sn (stannum), and Ti is titanium.
11.Which of these elements is a metalloid?
- A. Sodium
- B. Sulfur
- C. Silicon
- D. Neon
Answer: C. Silicon
Silicon sits on the staircase line between metals and nonmetals and behaves partly like each: it is a semiconductor, which is why it is used in chips. Sodium is a metal, sulfur is a nonmetal and neon is a noble gas. Most tables list boron, silicon, germanium, arsenic, antimony and tellurium as metalloids, though sources differ on a few more.
12.Moving down a group of main-group elements, atomic radius generally:
- A. decreases, because the nucleus holds the electrons tighter
- B. stays the same, because every atom in a group has the same valence electrons
- C. decreases and then increases at the bottom of the group
- D. increases, because each row adds an electron shell
Answer: D. increases, because each row adds an electron shell
Each new period adds an electron shell, so atoms get larger even though the nuclear charge grows. This is why a cesium atom is much bigger than a lithium atom. Across a period the trend runs the other way.
13.Complete the sentence.
Noble gases such as neon and argon rarely react because their outer electron shell is _____. They fill group _____ of the table.
Options for blank 1: full, empty, half full, metallic
Options for blank 2: 1, 2, 17, 18
Answer: full, 18
A full outer shell is very stable, so noble gases have little reason to gain, lose or share electrons. They fill group 18, the far-right column. Group 17 is the halogens, one electron short of a full shell, and group 1 is the alkali metals.
14.Which of these elements has the highest electronegativity?
- A. Oxygen
- B. Chlorine
- C. Fluorine
- D. Nitrogen
Answer: C. Fluorine
Electronegativity measures how strongly an atom pulls on shared electrons. It rises toward the upper right of the table, and fluorine, small and one electron short of a full shell, is the highest of all. The noble gases are left out of this trend because they rarely form bonds.
15.Which statements describe the general trend from left to right across a period of main-group elements? Select all that apply.
Select all that apply.
- A. Metallic character increases
- B. Atomic radius decreases
- C. First ionization energy increases
- D. The number of occupied electron shells increases
- E. Elements change from metals to nonmetals
Answer: B. Atomic radius decreases, C. First ionization energy increases, E. Elements change from metals to nonmetals
Across a period, protons are added while the new electrons go into the same shell, so the pull on the outer electrons grows. Atoms shrink, ionization energy rises with a few small dips, and elements go from metals on the left to nonmetals on the right. Metallic character therefore falls, and the number of shells stays the same within a period.
How the periodic table is organized
The modern periodic table lists 118 confirmed elements in order of atomic number, which is the number of protons in an atom's nucleus. It has 7 rows, called periods, and 18 columns, called groups. Moving left to right along a period, the atomic number goes up by one at each step. Moving down a group, you stay in one family of elements.
Elements in a group behave alike because the main-group ones have the same number of outer electrons, called valence electrons. Lithium, sodium and potassium in group 1 each have one, and all three react with water, more violently as you go down. The noble gases in group 18 have a full outer shell and barely react at all. Period 1 is short, with only hydrogen and helium. The long rows hold the transition metals in the middle, and two extra rows, the lanthanides and actinides, are usually drawn below the main block to keep the table narrow.
Metals fill the left and center, nonmetals sit toward the right, and a thin staircase line marks the metalloids between them, such as silicon. The newest four elements, 113, 115, 117 and 118, were officially named by IUPAC on 28 November 2016: nihonium, moscovium, tennessine and oganesson. That completed the seventh row.
How to use this quiz and what to learn first
The 15 questions are split into three on symbols and names, seven on reading the table, two on metals and metalloids and three on trends. Take it once without looking anything up, then read the explanation for every question, including the ones you got right. If you missed the group questions, learn the groups before you touch the trends, because the trends only make sense once you can find the right corner of the table.
Start with the eleven symbols that do not match the English name, because they trip people up the most: Na (sodium), K (potassium), Fe (iron), Cu (copper), Ag (silver), Au (gold), Hg (mercury), Pb (lead), Sn (tin), Sb (antimony) and W (tungsten). They come from older Latin or German names such as natrium, kalium, ferrum and wolfram. Most other symbols start with the same letter as the English name.
Then learn the first 20 elements, hydrogen through calcium, in order, and the names of the main groups: alkali metals, alkaline earth metals, halogens and noble gases. Many chemistry exams hand you a periodic table, so check what your course allows. Even then, knowing the structure lets you read the table in seconds. For electron configurations and bonding in depth, the AP Chemistry practice test linked below goes further than this quiz.
How to build more practice tests from your own materials
Fifteen questions can show you whether symbols, groups or trends need the most work. They cannot get you ready on their own, especially when your course stresses one part of chemistry more than another.
StudyPDF works from your material instead. Upload your chemistry slides, your class notes or a photo of the table from your textbook. Then press New material, pick a practice test or flashcards, choose those files as the sources and set how long it should be. You get a test written from those exact pages, and every explanation cites where the answer comes from.
Bo is the tutor for the rest. Ask why an answer is right and he explains it from your own pages, with a hint first if you want one.
You do not have to upload anything to start. Name a topic instead, for example group 17 or the first 20 elements, and you get practice questions on it. Starting is free.
Written by the StudyPDF team. Last updated August 19, 2026.
Good to know
Is this periodic table quiz free?
Yes. All 15 questions, the score screen and every explanation are free to use in your browser. There is no paywall on this page.
Do I need to memorize all 118 elements?
Usually not. Many chemistry exams and classroom tests hand you a periodic table, but check what yours allows. The first 20 elements, the eleven symbols that come from older names and the main groups are a sensible place to start, and knowing how to read the table covers much of the rest.
How many elements are on the periodic table?
118 confirmed elements. The four newest, 113, 115, 117 and 118, were officially named by IUPAC on 28 November 2016: nihonium (Nh), moscovium (Mc), tennessine (Ts) and oganesson (Og). That completed the seventh row. Researchers have looked for elements beyond it, but none has been confirmed so far.
Where do these questions come from?
The StudyPDF team wrote all 15 from standard first-year chemistry topics. None are taken from a textbook, a test bank or an exam. StudyPDF is not affiliated with IUPAC, NIST or any exam board. For the official periodic table, use the version IUPAC publishes.