All categories

3 years ago

PLS I NEED UR HELP QUICK ILL BRAINLIST Nd gIVE U 5 star. answer in full sentence!

Chemistry

1 answer:

Oxana [17]3 years ago

6 0

Explanation:

1) There are three sub atomic particles; protons, neutrons and electrons. Protons and Neutrons are found in the nucleus while electrons are found in orbitals outside the Nucleus.

2) No. This is not always the case. An example is sodium which has atomic mass of 23.

Atomic Mass = Neutrons + Protons

23 = Neutrons + 11

Neutrons = 23 - 11 = 12

In sodium there are 11 protons and 12 neutrons

You might be interested in

Helen recorded the following data about the half-life of a radioisotope. Radioactive Decay of Radioisotope A Grams of Radioactiv

MissTica

Answer:

Line graph

Explanation:

I did it on Study Island

7 0

3 years ago

Write the isotopic symbol for the following (show your work) a) An isotope of iodine whose atoms have 78 neutrons b) An isotope

morpeh [17]

Answer:

For a: The isotopic representation of iodine is $_{53}^{131}\textrm{I}$

For b: The isotopic representation of cesium is $_{55}^{137}\textrm{Cs}$

For c: The isotopic representation of strontium is $_{38}^{52}\textrm{Sr}$

Explanation:

The isotopic representation of an atom is: $_Z^A\textrm{X}$

where,

Z = Atomic number of the atom

A = Mass number of the atom

X = Symbol of the atom

For a:

We are given:

Number of neutrons = 78

Atomic number of iodine = 53 = Number of protons

Mass number = 53 + 78 = 131

Thus, the isotopic representation of iodine is $_{53}^{131}\textrm{I}$

For b:

We are given:

Number of neutrons = 82

Atomic number of cesium = 55 = Number of protons

Mass number = 55 + 82 = 137

Thus, the isotopic representation of cesium is $_{55}^{137}\textrm{Cs}$

For c:

We are given:

Number of neutrons = 52

Atomic number of strontium = 38 = Number of protons

Mass number = 38 + 52 = 90

Thus, the isotopic representation of strontium is $_{38}^{52}\textrm{Sr}$

3 0

3 years ago

Describe three signs that a chemical reaction has taken place and give an example of each sign

il63 [147K]

Color change, temperature change, bubbling, state change

green to blue, hot to cold, bubbles (lol), and liquid to gas

7 0

3 years ago

How many particles of Na are there in 1.43g of a molecular compound with a Molar mass of 23g?

Olin [163]

Answer:

3.74 x 10²² particles

Explanation:

Given parameters:

Mass of compound = 1.43g

Molar mass of compound = 23g

Unknown:

Number of particles of sodium = ?

Solution:

To find the number of particles of Na in the compound, we need to obtain the mass of sodium from the total mass given;

Mass of sodium = $\frac{molar mass of Na}{molar mass of compound} x mass of sample$

= $\frac{23}{23} x 1.43g$

= 1.43g

Now find the number of moles of this amount of Na in the sample;

Number of moles = $\frac{mass}{molar mass}$ = $\frac{1.43}{23}$ = 0.062mole

Now;

1 mole of substance = 6.02 x 10²³ particles

0.062 mole of substance = 0.062 x 6.02 x 10²³ particles

= 3.74 x 10²² particles

7 0

3 years ago

Please answer ASAP! Where on the Periodic Table are Transition Elements located?

igor_vitrenko [27]

c group A is the correct answer

6 0

3 years ago