Combined Tests on Matter and Experiments

Multiple Choice Questions - Combined Tests 1, 2, 3

• Matter: Has mass and volume.

• Controlled Experiment Variable: The independent variable is intentionally changed by the researcher.

• Controlling Factors in Experiments: Keeping all factors constant except the independent variable ensures changes are due to that variable only. The goal is that the experiment supports the hypothesis and does not refute it by controlling other factors.

• Goal of Experiments: The primary objective is to test a hypothesis and determine if the results support or refute it. Gathering a lot of data is helpful but only if its purpose is to test the hypothesis.

• Physical Properties: Identified using the five senses.

• Volume Definition: Three-dimensional space occupied by a substance.

• Density Calculation: Density (d) = mass (m) / volume (V)

• Measuring Volume of Irregular Objects: Use water displacement.

• Floating Objects: Objects with a density less than the density of water will float.

• Layering Liquids (No Mixing): Liquids layer according to their densities. Denser liquids sink below less dense ones.

• Homogeneous Mixtures: Uniform composition throughout.

• Separation Methods: Examples include distillation or filtration. Distillation separates a mixture based on differences in boiling points.

• Compounds: Fixed ratio of elements chemically combined. Retains individual properties of component elements and can't be separated with physical methods.

• Elements: Different elements have unique properties and ratios in their compounds.

• Chemical Change: Produces new substances with different properties compared to the original substance.

• Isotopes: Variants of an element with the same number of protons but different numbers of neutrons (different masses).

• Atom Structure: Protons and neutrons form the nucleus, while electrons are in orbit. Nucleus contains the positive charge, electrons surround the nucleus, and negatively charged.

• Neutrons: Neutrons are particles with mass in the nucleus that don't have an electrical charge.

• Atomic Number: Number of protons is an atoms key identifier in the arrangement of the modern periodic table.

• Mass number: Sum of protons and neutrons in an atom. Its value can vary for isotopes of the same element.

• Electron Configuration (Electron Distribution): Electron configuration describes the arrangement of electrons within energy levels (shells), which further divides into sub-levels (s,p,d,f).

• Energy Levels/Shells: Different energy levels or shells have different volumes and contain varying numbers of electrons.

• Quantized Energy: Electrons can only occupy specific energy levels, not intermediate values.

• Subatomic Particles: Protons (positive), electrons (negative), and neutrons (neutral).

• Atomic Structure Diagram: Shows the arrangement of protons, neutrons, and electrons in an atom.

• Electron Orbits / Orbital Distribution: Electrons fill orbitals in specific orders, and different orbitals have different shapes.

• Valence Electrons: Outermost electrons in an atom. These determine chemical behaviour.

• Period Number (in Periodic Table): Indicates the number of energy levels an element has.

• Electronegativity: The ability of an atom to attract electrons in a covalent bond.

• Rows in the Periodic Table: Indicate energy levels for atoms.

• Columns in the Periodic Table: Indicate patterns of similar valence electron configurations causing similar behaviour in atoms.

Test your knowledge with this quiz on key concepts related to matter, controlled experiments, and physical properties. Explore topics such as density calculations, volume measurement, and the goals of scientific experimentation. Perfect for students looking to reinforce their understanding of these fundamental science principles.