All categories

3 years ago

The atomic number of an element best corresponds to which of the following?

Chemistry

1 answer:

xenn [34]3 years ago

7 0

Answer: The number of protons in the nucleus of an atom of that element.

Explanation: the atomic number of an element is simply the proton number of that element. This is the most reason while the ion of a particular element still retain its atomic number whether it gains or loss electrons. For example, sodium atom (Na) has 11 electrons, 11 protons and 12 neutrons. Sodium ion (Na+) on the other hand has 10 electrons because it loss one electron, 11 proton and 12 neutrons. If the atomic number was to be determined by the number of electrons, then the atomic number of sodium atom and sodium ion would have been different. So the best way to determine the atomic number is by the number of protons. Neutron number will only bring about isotope and not atomic number

You might be interested in

Need help on this question asap please

3241004551 [841]

Answer:

The correct answer is - 14.

Explanation:

In the given molecular formula of the aluminum sulphite which is Al2(SO3)3, this molecular formula there different type of elements are bonded together to form this compound each element has a specific number of atoms present. This compound has three elements that are aluminum, sulfur, and oxygen and the atoms are present are:

Al = 2 atoms represented by subscript

S = 3 atoms represented as whole subscripts of sulfite

O = 9 atoms 3 inside bracket and 3 outside of bracket that multiplies.

Thus, total number of atoms are 2+3+9 = 14

3 0

2 years ago

The correct way of making a soluiton of acid in water is to

Talja [164]

Explanation:

To add acid into water to dilute the solution but don't add water into acid it can explosive/ can burnt to the victim

7 0

3 years ago

Graphite and iodine are non metal but they shine why secondry school

Alex_Xolod [135]

It is their properties. it is made up naturally due to the ions

8 0

3 years ago

An unknown salt is either NaF, NaCl, or NaOCl. When 0.050 mol of the salt is dissolved in water to form 0.500 L of solution, the

victus00 [196]

Answer: The unknown salt is NaF

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles of salt = 0.050 moles

Volume of solution = 0.500 L

Putting values in above equation, we get:

$\text{Molarity of salt}=\frac{0.050mol}{0.500L}\\\\\text{Molarity of salt}=0.1M$

To calculate the hydroxide ion concentration, we first calculate pOH of the solution, which is:

pH + pOH = 14

We are given:

pH = 8.08

$pOH=14-8.08=5.92$

To calculate pOH of the solution, we use the equation:

$pOH=-\log[OH^-]$

Putting values in above equation, we get:

$5.92=-\log[OH^-]$

$[OH^-]=10^{-5.92}=1.202\times 10^{-6}M$

The unknown salt given are formed by the combination of weak acid and strong acid which is NaOH

The chemical equation for the hydrolysis of $X^-$ ions follows:

$X^-(aq.)+H_2O(l)\rightleftharpoons HX(aq.)+OH^-(aq.);K_b$

Initial: 0.1

At eqllm: 0.1-x x x

Concentration of $OH^-=x=1.202\times 10^{-6}M$

The expression of $K_b$ for above equation follows:

$K_b=\frac{[OH^-][HX]}{[X^-]}$

Putting values in above expression, we get:

$K_b=\frac{(1.202\times 10^{-6})\times (1.202\times 10^{-6})}{(1-(1.202\times 10^{-6}))}\\\\K_b=1.445\times 10^{-11}M$

To calculate the acid dissociation constant for the given base dissociation constant, we use the equation:

$K_w=K_b\times K_a$

where,

$K_w$ = Ionic product of water = $10^{-14}$

$K_a$ = Acid dissociation constant

$K_b$ = Base dissociation constant = $1.445\times 10^{-11}$

Putting values in above equation, we get:

$10^{-14}=1.445\times 10^{-11}\times K_a\\\\K_a=\frac{10^{-14}}{1.445\times 10^{-11}}=6.92\times 10^{-4}$

We know that:

$K_a\text{ for HF}=6.8\times 10^{-6}$

$K_a\text{ for HCl}=1.3\times 10^{6}$

$K_a\text{ for HClO}=3.0\times 10^{-8}$

So, the calculated $K_a$ is approximately equal to the $K_a$ of HF

Hence, the unknown salt is NaF

6 0

3 years ago

How does a change in frequency or amplitude change the sound we hear

suter [353]

Pitch is sometimes defined as the fundamental frequency of a sound wave (i.e. generally, the lowest frequency in a given sound wave). For most practical purposes, this is fine, and pitch and frequency can be thought of as equivalent. On the other hand, for most practical purposes, amplitude can be thought of as volume.However, technically, pitch (and volume) are human perceptions. Thus, our perception of pitch and volume are not solely based on frequency and amplitude respectively, but are based on a combination of both (and even other factors). Frequency overwhelming dictates perceived pitch, but amplitude also does have some small, small effect on our pitch perception, especially when it is very large. For example, a very loud sound can have a different perceived pitch than you would predict from its frequency alone.That all being said, usually these effects are negligible, and pitch can be thought of as equivalent to fundamental frequency.

4 0

2 years ago