VALID Science 10 flashcards
VALID Science 10 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Independent variable
- The factor the experimenter deliberately changes between groups. It is the presumed cause, and its effect is judged by comparing the dependent variable across its levels.
- Control group
- A comparison group that receives no treatment or an inactive placebo. It isolates the effect of the independent variable by showing what happens without it.
- Accuracy versus precision
- Accuracy is how close a measurement is to the true value. Precision is how close repeated measurements are to each other, regardless of whether they are correct.
- Atomic number
- The number of protons in an atom's nucleus. It uniquely identifies the element and, in a neutral atom, equals the number of electrons.
- Valence electrons
- Electrons in the outermost shell of an atom. Their number determines chemical reactivity and matches the element's group number pattern in the periodic table.
- Isotope
- An atom of the same element with a different number of neutrons. Isotopes share proton count and chemistry but differ in mass number and stability.
- Conservation of mass
- In a closed system, the total mass of reactants equals the total mass of products. Atoms are rearranged in reactions but never created or destroyed.
- Balanced equation
- A chemical equation with coefficients adjusted so each element has equal atom counts on both sides. Only coefficients change; subscripts stay fixed.
- Exothermic reaction
- A reaction that releases energy to the surroundings, usually raising the temperature. Combustion and many neutralization reactions are exothermic.
- Catalyst
- A substance that increases reaction rate by lowering activation energy without being consumed. It is not part of the products and can be reused.
- Ionic bond
- An electrostatic attraction between oppositely charged ions formed when a metal transfers electrons to a nonmetal. The resulting compound is a crystal lattice.
- Covalent bond
- A bond formed when two nonmetal atoms share one or more pairs of electrons. The shared electrons hold the atoms together as a molecule.
- Binary ionic naming
- Name the metal first, then the nonmetal with an -ide ending, such as sodium chloride. Use Roman numerals when the metal has variable charge.
- Newton's second law
- Net force equals mass times acceleration (F = ma). Acceleration grows with applied force and shrinks as mass increases for the same force.
- Kinetic energy
- Energy of motion, calculated as one-half mass times velocity squared (KE = ½mv²). Doubling speed quadruples kinetic energy.
- Weight versus mass
- Mass is the amount of matter, measured in kilograms and constant. Weight is the gravitational force on that mass, measured in newtons and varying with gravity.
- Ohm's law
- Voltage equals current times resistance (V = IR). For fixed resistance, increasing voltage increases current proportionally.
- Parallel circuit
- A circuit with multiple branches across the same voltage. Current divides among branches, and total resistance is less than the smallest branch resistance.
- Electrical power
- The rate of energy transfer in a circuit, equal to voltage times current (P = VI). It is measured in watts.
- Divergent boundary
- A plate boundary where plates move apart. Magma rises to form new crust, producing mid-ocean ridges, rift valleys, and shallow earthquakes.
- Subduction zone
- A convergent boundary where denser oceanic crust sinks beneath another plate. It creates deep trenches, volcanic arcs, and powerful earthquakes.
- Epicenter
- The point on Earth's surface directly above the focus of an earthquake. It usually experiences the strongest shaking.
- Relative humidity
- The amount of water vapor in air expressed as a percentage of the maximum the air could hold at that temperature. Cooling raises it toward saturation.
- Air pressure
- The force exerted by the weight of air above a point. It decreases with altitude, and air moves from high to low pressure as wind.
- Greenhouse effect
- Atmospheric gases absorb and re-emit infrared radiation from Earth's surface, keeping the planet warmer than it would otherwise be.
- Mitosis versus meiosis
- Mitosis produces two identical diploid cells for growth and repair. Meiosis produces four genetically varied haploid gametes for sexual reproduction.
- Genotype versus phenotype
- Genotype is an organism's allele combination, such as heterozygous. Phenotype is the observable trait produced by that combination and the environment.
- Punnett square
- A grid predicting offspring genotypes from parental alleles. A cross of two heterozygotes gives a 1:2:1 genotype ratio.
- Trophic level
- A feeding position in a food chain, such as producer or primary consumer. Roughly ten percent of energy passes to the next level.
- Carrying capacity
- The maximum population size an ecosystem can sustain given available food, water, space, and other limiting factors. It can shift with environmental change.
- Biodiversity
- The variety of species and genetic variation within an ecosystem. Higher biodiversity generally increases resilience to disturbance and environmental change.
- Decomposer
- An organism such as bacteria or fungi that breaks down dead matter and wastes, releasing nutrients back into the ecosystem for producers to reuse.