Answer:The 2nd and 3rd one.
Explanation:
It has the same number of protons but different amount of nuetrons.
Answer:0.00000009
Explanation:
9.11 × （1/1000000000）=0.00000009
Explanation:
A clastic sedimentary rock is a rock that is formed from pre-existing rock materials and minerals. This materials have been transported to their new positions by the agents of denudation.
- Clastic sedimentary rocks are made up of rock fragments predominantly.
- The matrix is usually remnants of other rocks.
- A cementing material can form between clasts and holds them in place. Cements are usually iron oxides, calcite e.t.c.
- These rock types are usually formed from mechanincal weathering of rocks
- Mechanical weathering breaks down rocks into chunks.
- Examples are breccia, conglomerates, e.t.c.
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Answer:
The gecko's feet have tiny suction cups on them that stick to the surface.
The reaction of iron (III) oxide and aluminum is initiated by heat released from a small amount "starter mixture". This reaction is an oxidation-reduction reaction, a single replacement reaction, producing great quantities of heat (flame and sparks) and a stream of molten iron and aluminum oxide which pours out of a hole in the bottom of the pot into sand.
The balanced chemical equation for this reaction is:
2 Al(s) + Fe2O3(s) --> 2Fe(s) + Al2O3(s) + 850 kJ/mol
Curriculum Notes
This chemical reaction can be used to demonstrate an exothermic reaction, a single replacement or oxidation-reduction reaction, and the connection between ∆H calculated for this reaction using heats of formation and Hess' Law and calculating ∆H for this reaction using qrxn = mc∆T and the moles of limiting reactant. This reaction also illustrates the role of activation energy in a chemical reaction. The thermite mixture must be raised to a high temperature before it will react.
To determine how much thermal energy is released in this reaction, heats of formation values and Hess' Law can be used.
By definition, the deltaHfo of an element in its standard state is zero.
2 Al(s) + Fe2O3(s) --> 2Fe (s) + Al2O3 (s)
The deltaH for this reaction is the sum of the deltaHfo's of the products - the sum of the deltaHfo's of the reactants (multiplying each by their stoichiometric coefficient in the balanced reaction equation), i.e.:
deltaHorxn = (1 mol)(deltaHfoAl2O3) + (2 mol)(deltaHfoFe) - (1 mol)(deltaHfoFe2O3) - (2 mol)(deltaHfoAl)
deltaHorxn = (1 mol)(-1,669.8 kJ/mol) + (2 mol)(0) - (1 mol)(-822.2 kJ/mol) - (2mol)(0 kJ/mol)
deltaHorxn = -847.6 kJ
The melting point of iron is 1530°C (or 2790°F).
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