First, isotopes <u>are the atoms of a single element whose nuclei have a different number of neutrons</u>, and therefore, differ in mass numbers. You should know that atoms are formed by a nucleus that has a small size and is made up of protons and neutrons. The nucleus is surrounded by a cloud of electrons, which are found in a region of the atom called the cortex.
The mass number, represented as A, <u>is the sum of the number of protons and neutrons in the nucleus</u>. On the other hand, the atomic number (Z) is <u>the number of protons that exist in the nucleus.
</u>
The isotopes of an element X are represented as follows,
<em>(see first attached picture)</em>
It should be noted that the number of neutrons of a chemical element can be calculated as the difference A-Z.
<u>The atomic and mass numbers of bismuth with 125 neutrons are</u>:
Z = 83
A = 83 + 125 = 208
Thus, the atomic symbol of the bismuth isotope with 125 neutrons is:
<em>(see second attached picture)</em>
The number of molecules decrease
Answer:
Matter
Explanation:
All matter is made up of substances called elements
The amount of heat transferred in and out of the system is measured by calorimetry. The thermometer in the calorimeter is used to measure the temperature.
<h3>What are the parts of the calorimetry device?</h3>
The thermometer (A) is a device used to measure the final and the initial temperature of the water or any other liquid in a system. A metal vessel is a place where the reaction mixture is present.
In-vessel (B), water, and metal are placed before the beginning of the experiment. The styrofoam cup or the outer metal vessel (C) insulates the instrument, from regulating the heat transformation.
Therefore, part A measures the temperature of the reaction mixture.
Learn more about insulated containers here:
brainly.com/question/866735
Answer:
Liquids, because they flow, can occupy whatever shape their container has, so they do not have a fixed shape. Because the particles in liquids are very close together (barely further apart than in solids) liquids do not easily compress, so their volume is fixed. hope that helps love!