Untitled Flashcards Set

🧪 CHEMISTRY – PERIODIC TABLE

Q: What does the atomic number represent?
A: Number of protons (and also electrons in a neutral atom).

Q: What is the atomic mass?
A: Number of protons + neutrons.

Q: What does a group on the periodic table show?
A: Number of valence electrons.

Q: What does a period on the periodic table show?
A: Number of electron shells.

Q: How does reactivity change down a group?
A: Metals: more reactive ⬇
Non-metals: less reactive ⬇

Q: What is atomic radius?
A: Distance from nucleus to valence shell.

Q: What happens to atomic radius down a group?
A: Increases.

Q: What’s the electron arrangement for the first 20 elements?
A: 2, 8, 8, 2

Q: Characteristics of alkali metals?
A: Highly reactive, loosely held outer electrons.

Q: Characteristics of noble gases?
A: Unreactive, full valence shell.

Q: Which elements are more likely to lose electrons?
A: Ones with large atomic radius (metals).

Q: Which elements are more likely to gain electrons?
A: Ones with small atomic radius (non-metals).

🔗 CHEMISTRY – BONDING

Q: What is an ionic bond?
A: Electrostatic attraction between oppositely charged ions.

Q: How is an ionic bond formed?
A: Metal transfers electrons to non-metal.

Q: Structure of ionic compounds?
A: Crystal lattice.

Q: Physical properties of ionic compounds?
A: Solid at room temp, high melting point.

Q: What is a covalent bond?
A: Sharing of valence electrons between two non-metals.

Q: What holds atoms together in covalent bonding?
A: Shared electrons (bonding electrons).

Q: What is the difference between polar and non-polar covalent bonds?
A: Polar = unequal sharing
Non-polar = equal sharing

Q: Examples of covalent molecules?
A: H₂O (polar), O₂ (non-polar)

Q: State and melting point of covalent compounds?
A: Can be gas, liquid, or soft solid. Low melting points.

🔬 Comparison Table Quick Hits

Q: Bond type: Metal + Non-metal?
A: Ionic bond

Q: Bond type: Non-metal + Non-metal?
A: Covalent bond

Q: Ionic compounds share electrons?
A: No – they transfer electrons.

Q: Covalent compounds share electrons?
A: Yes – they share to fill valence shells.

Q: Which is stronger: ionic or covalent?
A: Ionic – strong electrostatic forces.
🧬 BIOLOGY – CHROMOSOMES & KARYOTYPES

Q: What is a chromosome?
A: A thread-like structure made of DNA that carries genes.

Q: How many chromosomes do humans have?
A: 46 (23 pairs)

Q: What are homologous chromosomes?
A: A pair of chromosomes, one from each parent, that are the same size and shape and carry genes for the same traits.

Q: What is a karyotype?
A: An image showing the complete set of chromosomes in a cell.

Q: What is the sex chromosome combo for females?
A: XX

Q: What is the sex chromosome combo for males?
A: XY

Q: What can a karyotype show?
A: Chromosome number, sex, and chromosomal disorders (e.g. Down syndrome).

🧫 MITOSIS

Q: What is mitosis?
A: Cell division that produces two identical daughter cells for growth and repair.

Q: How many cells are made in mitosis?
A: 2 identical diploid cells.

Q: Is mitosis used for reproduction?
A: No – used for growth, repair, and replacement.

Q: Are mitotic cells genetically identical?
A: Yes – clones of the parent cell.

Q: Stages of mitosis?
A: PMAT – Prophase, Metaphase, Anaphase, Telophase (followed by cytokinesis).

🧬 MEIOSIS

Q: What is meiosis?
A: Cell division that makes gametes (sperm and egg) with half the number of chromosomes.

Q: How many cells are made in meiosis?
A: 4 non-identical haploid cells.

Q: What is the purpose of meiosis?
A: Sexual reproduction – increases genetic variation.

Q: How does meiosis cause variation?
A: Crossing over and independent assortment.

Q: Difference between mitosis and meiosis?
A: Mitosis = 2 identical diploid cells
Meiosis = 4 different haploid cells

🧬 INHERITANCE – BASIC GENETICS

Q: What is a gene?
A: A segment of DNA that codes for a trait.

Q: What is an allele?
A: A version of a gene (e.g. blue vs brown eyes).

Q: What is a genotype?
A: The genetic makeup (e.g. Bb, bb).

Q: What is a phenotype?
A: The physical trait shown (e.g. blue eyes).

Q: What does dominant mean?
A: Trait that shows even if only one allele is present (e.g. B).

Q: What does recessive mean?
A: Trait only shows if both alleles are recessive (e.g. b).

Q: What is homozygous?
A: Two of the same alleles (BB or bb).

Q: What is heterozygous?
A: Two different alleles (Bb).

🧬 PUNNETT S SEX-LINKED TRAITS

Q: What does a Punnett square show?
A: Possible offspring genotypes and phenotypes.

Q: Probability of Bb x Bb having a bb child?
A: 25%

Q: What are sex-linked traits?
A: Traits carried on the X chromosome (e.g. colourblindness, haemophilia).

Q: Why are males more likely to show X-linked recessive traits?
A: They only have one X chromosome – if it has the gene, they express it.

Q: Female carriers of X-linked traits have what genotype?
A: XᴺXⁿ (one normal, one affected)

🧬 PEDIGREES

Q: What is a pedigree?
A: A diagram that shows how traits are inherited across generations.

Q: What does a shaded shape mean in a pedigree?
A: The person shows the trait.

Q: What shape represents a male?
A: Square.

Q: What shape represents a female?
A: Circle.

Q: What does it mean if a trait skips a generation?
A: Likely recessive.

Q: How can you tell if a trait is sex-linked in a pedigree?
A: More males affected, often passed from mothers to sons.
Q: What is distance?
A: The total length of the path travelled, a scalar quantity (no direction).

Q: What is displacement?
A: The shortest straight-line distance between the starting and ending point, a vector quantity (has direction).

Q: Difference between distance and displacement?
A: Distance is the total path length, while displacement is the straight-line distance with direction.

Q: What is speed?
A: The rate at which an object moves. Formula: Speed = Distance ÷ Time.

Q: What is velocity?
A: The rate of change of displacement, with direction. Formula: Velocity = Displacement ÷ Time.

Q: Is velocity scalar or vector?
A: Vector – it has both magnitude (speed) and direction.

📊 GRAPHING MOTION

Q: What does a distance-time graph show?
A: It shows how distance changes over time.

Q: What does a flat horizontal line mean on a distance-time graph?
A: The object is stationary.

Q: What does a steeper slope on a distance-time graph indicate?
A: The object is moving faster.

Q: What does a velocity-time graph show?
A: It shows how velocity changes over time.

Q: What does a flat horizontal line on a velocity-time graph mean?
A: The object is moving at a constant velocity.

Q: What does the area under a velocity-time graph represent?
A: The total displacement of the object.

Q: What does a negative slope on a velocity-time graph indicate?
A: The object is decelerating.