What are the basic units that all matter is made of?

What was the significance of Thompson’s Plum Pudding model of the atom?

Pani-rosa [81]

The Plum Pudding Model is a model of atomic structure proposed by J.J. Thomson in the late 19th century. Thomson had discovered that atoms are composite objects, made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom.

6 0

3 years ago

N2H4 + N2O4 --> N2 + H2O

givi [52]

Answer:

Explanation:

Since this problem is incomplete, let us give a simple explanation to solve it.

In any reaction, we always have reactants that are in short supply and those that are in excess.

A reactant in short supply in a reaction is called the limiting reagent. This reactant will usually determine the extent of the reaction. When it is used up, the reaction will stop and will not proceed further.

To solve for the limiting reagent, convert the given mass to number of moles. Always work with number of moles.

Then write the balanced reaction equation.

Compare the moles from the balanced equation to that obtained. The reacting specie that is lesser in proportion is the limiting reagent

To solve the second part;

Compare the number of moles of the limiting reactant to that of the product i.e H₂O;

Use this number of moles to find mass;

Mass of H₂O = number of moles x molar mass

6 0

3 years ago

Magnesium has three stable isotopes. One has 12 neutrons the second has 13 and the third has 14. Which one is the most abundant?

fiasKO [112]

Answer:

12

Explanation:

If you look at the periodic table, you can see that magnesium has an atomic mass of 24.305. Subtract the number of protons from this to get neutrons.

24.305 - 12 = 12.305

12.305 is the average amount of neutrons a magnesium atom can have. A magnesium atom can have 12, 13, or 14 neutrons. The average, based on the natural abundance, is 12.305. To find which isotope is more abundant, you need to pick the number that is closest to the average. This would make the most abundant isotope the one with 12 neutrons.

7 0

3 years ago

If an ion has a charge of 1-, the ion must have A. More electrons than neutrons. B. More protons than electrons. C. More electro

anyanavicka [17]

Answer:

C

Explanation:

when an ion has a 1- charge it gains 1 electron. when an atom is neutral, it has the same protons as electrons.

7 0

3 years ago

1. The element copper has naturally occurring isotopes with mass numbers of 63 and 65. The relative abundance and atomic masses

Basile [38]

Answer: The average atomic mass of copper is 63.546 amu

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For isotope 1 (Cu-63):

Mass of isotope 1 = 62.93 amu

Percentage abundance of isotope 1 = 69.2 %

Fractional abundance of isotope 1 = 0.692

For isotope 2 (Cu-65):

Mass of isotope 2 = 64.93 amu

Percentage abundance of isotope 2 = 30.8 %

Fractional abundance of isotope 2 = 0.308

Putting values in equation 1, we get:

$\text{Average atomic mass of Copper}=[(62.93\times 0.692)+(64.93\times 0.308)]\\\\\text{Average atomic mass of Copper}=63.546amu$

Hence, the average atomic mass of copper is 63.546 amu

8 0

3 years ago