The depletion of natural resources, the use of chemical and fuel in factories that increased air and water pollution , and increased the use of fossil fuels.
Answer:
The correct answers are:
a) 180 g
b) 93.7 cm³
Explanation:
The density of a substance is the mass of the substance per unit of volume. So, it is calculated as follows:
density= mass/volume
From the data provided in the problem:
density = 0.8 g/cm³
a) Given: volume= 225 cm³
mass= density x volume = 0.8 g/cm³ x 225 cm³ = 180 g
b) Given: mass= 75.0 g
volume = mass/density = 75.0 g/(0.8 g/cm³)= 93.75 cm³≅ 93.7 cm³
<span>Answer: option (3) energy, charge and mass.
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<span>Explanation:
</span><span />
<span>1) The conservation of energy is a universal principle: energy is neither created nor destroyed. This is the first law of thermodynamic.
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<span>2) Mass conservation is another universal principle: mass is neither created nor destroyed. This principle is the base of the stochiometry: thas mass of the reactans equal the mass of the products. Another consequence, since the atoms are not transformed in the chemical reactions, is that the number of each kind of atoms in the reactants equal the number of the same kind of atoms in the products.
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<span>3) The third principle is the conservation of charge. Also, charge is neither created nor destroyed. The electrons gained/lost by one species are lost/gained by other species. So, when one atom or molecule is oxidized other is reduced.</span>
(of a river or road) follow a winding course
<span>Answer is 6.66 mol.
<em>Explanation:</em>
According to the
Avogadro's constant, 1 mole of substance has 6.022 × 10²³ particles.
Number of Zinc atoms = </span>4.01 x 10²⁴
Avogadro's constant = 6.022 × 10²³ mol⁻¹
Hence,
moles of Zinc = number of Zinc atoms / Avogadro's constant
= 4.01 x 10²⁴ / 6.022 × 10²³ mol⁻¹
= 6.66 mol
