Practice Test GeeksGCSE - General Certificate of Secondary Education Practice Test
← All GCSE Flashcard Decks

Atomic Structure & Periodic Table Flashcards

7 cards from real GCSE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Atomic Structure & Periodic Table flashcards as text

  1. An element has 17 protons and 18 neutrons. What is its mass number?

    Answer: 35

    Mass number = protons + neutrons = 17 + 18 = 35.

  2. Which of the following best describes isotopes of the same element?

    Answer: Same atomic number, different number of neutrons

    Isotopes have the same atomic number (protons) but differ in neutron count, giving different mass numbers.

  3. In the modern periodic table, elements are arranged in order of increasing:

    Answer: Atomic number

    Mendeleev used atomic mass, but the modern periodic table orders elements by atomic number (number of protons).

  4. Which subatomic particle determines the chemical properties of an element?

    Answer: Electrons

    Electrons, especially the outermost shell electrons, determine how an element reacts chemically.

  5. Sodium has atomic number 11. How many electron shells does a sodium atom have?

    Answer: 3

    Sodium's electron configuration is 2,8,1 — filling three shells.

  6. What happens to the atomic radius as you move across a period from left to right?

    Answer: It decreases

    Atomic radius decreases across a period because increasing nuclear charge pulls electrons closer without adding a new shell.

  7. Which group in the periodic table contains the alkali metals?

    Answer: Group 1

    Alkali metals (Li, Na, K, etc.) are in Group 1 and have one electron in their outermost shell.