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Salt crystals are shaped like cubes. Salt is part of the _____. isometric crystal system monoclinic crystal system hexagonal cry

sweet [91]

Salt crystals are shaped like cubes. Salt is part of the isometric crystal system.

6 0

3 years ago

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What is most likely the ph of a solution containing many hydroxide ions (oh-) and few hydrogen ions (h )?

SIZIF [17.4K]

PH of solution will be greater than seven (pH>7), that means that solution is basic (pH above 7 is a base, the higher the number, the stronger is the base).
pH (potential of hydrogenis) is a measure of the hydrogen ion (H⁺) concentration of a solution. Solutions with a pH less than 7 are acidic.

5 0

3 years ago

It is known that the kinetics of recrystallization for some alloy obey the Avrami equation andthat the value of n in the exponen

Paul [167]

Answer:

rate of recrystallization = 4.99 × 10⁻³ min⁻¹

Explanation:

For Avrami equation:

$y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ k = \dfrac{-In(1-y)}{t^n}$

To calculate the value of k which is a dependent variable for the above equation ; we have:

$k = \dfrac{-In(1-0.40)}{200^{2.5}}$

$k = 9.030 \times 10 ^{-7}$

The time needed for 50% transformation can be determined as follows:

$y = 1-e ^{(-kt^n)} \\ \\ e^{(-kt^n)} = 1-y\\ \\ -kt^n = In(1-y) \\ \\ t =[ \dfrac{-In(1-y)}{k}]^{^{1/n}}$

$t_{0.5} =[ \dfrac{-In(1-0.4)}{9.030 \times 10^{-7}}]^{^{1/2.5}}$

= 200.00183 min

The rate of reaction for Avrami equation is:

$rate = \dfrac{1}{t_{0.5}}$

$rate = \dfrac{1}{200.00183}$

rate = 0.00499 / min

rate of recrystallization = 4.99 × 10⁻³ min⁻¹

8 0

3 years ago

Which of the following is not true of a scientific theory?

Furkat [3]

Answer: a,b

Explanation: because a scientific theory is something that been thought of and tested multiple times.

3 0

3 years ago

Submit Quiz Previous Page 1 of 4 Next Drag and drop each description to match the subatomic particle. Protons Neutrons Drag and

Pavel [41]

Answer:

Protons:

Positively charged particle

The number of these is the atomic number

All atoms of a given element have the same number of these

Neutrons:

Neutral particles

Isotopes of a given element differ in the number of these

The mass number is the number of these added to the number of protons

Explanation:

Protons (positively charged), neutrons (neutral) and electrons (negatively charged) are smaller than an atom and they are the main subatomic particles. The nucleus of an atom is composed of protons and neutrons, and the electrons are in the periphery at unknown pathways.

The Atomic number (Z) indicates the number of protons ( $P^{+}$ ) in the nucleus. Every atom of an element have the same atomic number, thus the same number of protons.

The mass number (A) is the sum of the number of protons ( $P^{+}$ ) and neutrons (N) that are present in the nucleus: A= Z + N

Isotopes are atoms of the same element which nucleus have the same atomic number (Z), and different mass number (A), it means the same number of protons ( $P^{+}$ ) and a different number of neutrons (N). For example, the oxygen in its natural state is a mixture of isotopes:

99.8% atoms with A= 16, Z=8, and N=8

0.037% atoms with A=17, Z=8, and N=9

0.204% atoms with A=18, Z=8, and N=10

3 0

4 years ago