All categories

3 years ago

There are seven types of crystals. Which of these is not one of the seven?

Chemistry

2 answers:

kondor19780726 [428]3 years ago

4 0

Answer:

B- Tetraclinic

Explanation:

According to the similarity of their symmetry elements, thirty-two classes are grouped into seven crystal systems: isometric (cubic) system, tetragonal system, hexagonal system, trigonal system (subdivision of the hexagonal system, second North American school of crystallography). , called rhombohedral hexagonal system), orthorhombic system, monoclinic system and triclinic system. Applying the symmetry operations on all possible reticular planes (potential crystal faces) in the seven crystalline systems, according to the 32 symmetry classes, only 48 geometric shapes are possible to be obtained.

Gelneren [198K]3 years ago

3 0

The answer is B. tetraclinic

You might be interested in

Describe the concept of using radioactive elements to establish an age for a fossil. Be sure to include how the parent and daugh

Nadusha1986 [10]

Answer:

The nuclear decay of radioactive elements is a process that is a useful tool for determining the absolute age of fossils and rocks. It is used as a clock, in which daughter elements or isotopes converted from parent isotopes by decaying at a particular time.

Radioactive decay rates are constant and do not change over time. It is measured in half-life. A half-life is a time it takes half of a parent isotope to decay and converted into a stable daughter isotope. How many parent isotopes and daughter isotopes present in the fossil or their abundance can help in determining the age of fossil or rock.

4 0

3 years ago

How many electrons in an atom can have each of the following quantum number or sublevel designations?

lutik1710 [3]

Answer: a:6 electrons, b:10electrons, c: 2electrons

Explanation:

1.Principle quantum number(n)

n is the number of shell, it is a positive integer. The maximum number of electrons in a shell is 2(n2)

2.Azimuthal quantum number(l)

l is the number of subshell in the principal shell

The name of subshell are s, p, d, f

The number of nodes in each subshell is

s is l=0, p is l=1, d is l=2, f is l=3.

Each shell can have 2 x l + 1 sublevels, and each sublevel can accommodate maximum of 2 electrons and have two electrons.

A. n=2, l=1 then 2 x 1 + 1= 3 subshell, 3*2= 6 electrons in the p subshell

b. 3d, d is l = 2 then 2 x 2 + 1 = 5 sublevels, 5*2=10 electrons in the d subshell

c. 4s, s is l=0 then 2 x 0 + 1 = 1 sublevel, 1*2=2 electrons in the s subshell.

6 0

3 years ago

The relatively high boiling point of water is due to water having

Verizon [17]

The answer should be hydrogen bonding. Water only has oxygen and hydrogen in it, which are both nonmetals, so you know the answer cannot be metallic or ionic. It also cannot be nonpolar because the electronegativity of the oxygens will make the molecule polar. You can also know it is hydrogen bonding because it can only take place when a hydrogen is attached to an oxygen, fluorine, or nitrogen. These bonds are very strong attractions, so the molecules are extremely hard to pull apart, creating a high boiling point. Hope that helps!

3 0

3 years ago

Write the balanced chemical equation between H2SO4 and KOH in aqueous solution. This is called a neutralization reaction and wil

emmainna [20.7K]

Answer:

0.166M

Explanation:

In a neutralization, the acid, H₂SO₄, reacts with a base, KOH, to produce a salt, K₂SO₄ and water. The reaction is:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

To solve this problem, we need to determine moles of H2SO4 and moles of KOH that reacts to find the moles of sulfuric acid that remains after the reaction:

<em>Moles H2SO4:</em>

0.650L * (0.430mol /L) = 0.2795moles H2SO4

<em>Moles KOH:</em>

0.600L * (0.240mol / L) = 0.144 moles KOH

Moles of sulfuric acid that reacts with 0.144 moles of KOH are:

0.144 moles KOH * (1mol H2SO4 / 2 mol KOH) = 0.072 moles of H2SO4 react.

And remain:

0.2795moles H2SO4 - 0.072moles H2SO4 = 0.2075 moles of H2SO4 reamains.

In 0.650L + 0.600L = 1.25L:

Molar concentration of sulfuric acid:

0.2075 moles of H2SO4 / 1.25L =

7 0

3 years ago

Identify the base-conjugate acid pair in this balanced equation:

Elan Coil [88]

<h3><u>Answer;</u></h3>

NH3/NH4+

<h3><u>Explanation;</u></h3>

From the equation;

NH3(aq)+HNO3(aq)→NH4+(aq)+NO3−(aq)

NH3 is the base; while NH4+ is the conjugate acid

HNO3 is the acid; while NO3- is the conjugate base

The conjugate base of a Brønsted-Lowry acid is species that is formed after an acid donates a proton while the conjugate acid of a Brønsted-Lowry base is the species formed after a base accepts a proton.

3 0

3 years ago

Read 2 more answers