A four cycle engine works with 4 basic steps to a successful rotation of the crankshaft: the intake, compression, power and exhaust stroke. Each engine cylinder has four openings for the intake, exhaust, spark plug and fuel injection. ... The compression makes the air-fuel combination volatile for easier ignition.
Answer:
Extinction event or sometimes known as Mass extinction
Explanation:
These events typically are typically widespread and rapid decrease in the biodiversity (which takes into account spread and existence of current species). The worst mass extinction was Permian–Triassic extinction where over 90% of species of organisms vanished.
5. 25 x 10⁻⁷mg
Explanation:
This is mass conversion from mg to kg;
The kg is a quantity of mass used to measure the amount of matter in a substance.
Given mass = 5.25 x 10⁻¹³kg
The kilo- is a prefix that denotes 10³
therefore;
1000g = 1kilogram
the milli- is a prefix that denotes 10⁻⁻³
1000mg = 1g
Now that we know this, we can convert:
5.25 x 10⁻¹³kg x 
= 5. 25 x 10⁻¹³ x 10⁶mg
= 5. 25 x 10⁻⁷mg
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Conversion brainly.com/question/1548911
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Enthalpy of formation is calculated by subtracting the total enthalpy of formation of the reactants from those of the products. This is called the HESS' LAW.
ΔHrxn = ΔH(products) - ΔH(reactants)
Since the enthalpies are not listed in this item, from reliable sources, the obtained enthalpies of formation are written below.
ΔH(C2H5OH) = -276 kJ/mol
ΔH(O2) = 0 (because O2 is a pure substance)
ΔH(CO2) = -393.5 kJ/mol
ΔH(H2O) = -285.5 kJ/mol
Using the equation above,
ΔHrxn = (2)(-393.5 kJ/mol) + (3)(-285.5 kJ/mol) - (-276 kJ/mol)
ΔHrxn = -1367.5 kJ/mol
<em>Answer: -1367.5 kJ/mol</em>
Explanation:
Mole ratio of NH3 to NaNH2 = 2 : 2.
Moles of NaNH2 produced
= 4.3mol * (2/2) = 4.3mol.
