Earth Physics
This completely empty space contains no particles at all, making it impossible for sound waves to travel through it.
What is a vacuum?
Microorganisms are classified under this general term because they are too small to be seen clearly without the aid of this scientific instrument.
What is a microscope?
This type of alteration, such as melting ice or dissolving sugar in water, does not produce any completely new chemical substances.
What is a physical change?
This chemical scale ranges from 0 to 14 and is used by scientists to measure the relative strength of an acid or an alkali.
What is the pH scale?
This essential item provides the electrical push, or voltage, required to drive an electric current around a closed circuit.
What is a cell?
This is the thickest layer of the Earth, located directly beneath the crust, and is made of slow-flowing molten rock called magma.
What is the mantle?
This living, single-celled organism belongs to the fungi kingdom and is widely used in baking to make bread dough expand and rise.
What is yeast?
These are the initial starting materials written on the left-hand side of a chemical word equation before a reaction takes place.
What are reactants?
This common laboratory indicator tool turns a vibrant red color when dipped into an acid and a deep blue color when dipped into an alkali.
What is litmus paper?
This term describes the continuous flow of electrical charge moving through the wires and components of a functional circuit.
What is electric current?
This type of astronomical event occurs specifically when the Moon passes directly between the Sun and the Earth, casting a small shadow on Earth's surface.
What is a solar eclipse?
This gas byproduct is released during yeast respiration and becomes trapped inside dough to create light, fluffy air pockets.
What is carbon dioxide?
Rapid bubbling, fizzing, or effervescence observed during a reaction provides immediate visual evidence that this has been produced.
What is a gas?
These are bases that can dissolve completely in water, feel distinctly soapy to touch, and have a pH value greater than 7.
What are alkalis?
This specific scientific instrument must be connected directly into a circuit loop in series to measure the size of the current in amperes.
What is an ammeter?
This geological feature is formed at a convergent boundary when two continental tectonic plates collide, causing rock layers to compress and crumple upwards.
What are fold mountains?
This critical ecological process, carried out by specialized microbes, breaks down dead organic matter and recycles vital nutrients back into the soil.
What is decomposition (or decay)?
When solid magnesium ribbon is burned in the presence of oxygen gas, this specific white powder chemical compound is formed as the product.
What is magnesium oxide?
This type of chemical reaction occurs when an acid is mixed with an exact equivalent amount of an alkali, canceling each other out.
What is a neutralisation reaction?
In this specific type of circuit layout, all components are connected end-to-end in a single loop, creating only one single path for current to follow.
What is a series circuit?
If you stand near a cliff and shout, the sound travels to the rock face and reflects back. Because of this rule, the total distance traveled by the sound wave is calculated as this.
What is double the actual distance to the cliff?
Storing food inside a refrigerator at 4 degrees Celsius keeps it fresh because the cold environment does this to the microorganisms' enzymes.
What is slows down their activity (or rate of reaction)?
Unlike physical changes, chemical reactions are categorized as permanent changes because they are usually described as this.
What is very difficult to reverse?
When hydrochloric acid reacts completely with sodium hydroxide, the two neutral products formed are water and this specific chemical salt.
What is sodium chloride?
If you connect two additional cells in a row into a working series circuit with a single lamp, this will happen to the lamp's brightness.
What is it will increase (or burn brighter)?