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3 years ago

An increase in the atomic number________the atomic radius moving from left to right across a period.

Chemistry

1 answer:

frez [133]3 years ago

4 0

Answer:

decrease

Explanation:

Atomic radius :

It is the distance from the center of nucleus to the outer most electronic shell.

Trend along period:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required

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-Dominant- [34]

Answer:

The answer is SiO2

Explanation:

Silocon dioxide is written without a 1 after the silocon and with a 2 after the oxygen.

4 0

3 years ago

How can the law of conservation of<br> mass for a chemical reaction be expressed?

djverab [1.8K]

Answer:

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.

Explanation:

How does the concept of conservation of mass apply to chemical reactions? the reactants and products have exactly the same atoms. the reactants and products have exactly the same molecules. the change in the amount of matter is equal to the change in energy.

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5 0

3 years ago

Epinephrine (adrenaline) is a hormone secreted into the bloodstream in times of stress. It contains 59.0% C, 7.15% H, 26.20% O,

vichka [17]

Answer:

C9H13O3N

Explanation:

Take the atomic mass of C=12.0, H=1.0, O=16.0 and N=14.0.

We can draw a chart (please view this on desktop so to avoid spacing errors):

Let the mass of Epinephrine be 100g.

C H O N

mass(g) : 59 7.15 26.2 7.65

no. of moles : 59/12 =4.9167 7.15/1 = 7.15 26.2/16=1.6375 7.65/14=0.5464

(n.o.m. = mass/molar mass)

Ratio: 4.9167/0.5464 =9 7.15/0.5464=13 1.6375= 3 0.5464/0.5464 =1

(divide the n.o.m. by the smallest n.o.m., which is 0.5464 in this case, take the whole numbers)

So, the empirical formula will be: C9H13O3N

But this is still not yet the molecular formula. We have to ensure the molar mass is 183g/mol. Multiply the empirical formula by n.

So, let the molecular formula of Epinephrine be (C9H13O3N)n.

12x9n + 1x13n + 16x3n + 14n = 183

108n + 13n + 48n + 14n = 183

183 n = 183.

n = 1

Hence, the molecular formula is C9H13O3N.

3 0

3 years ago

Mercury can be obtained by reacting mercury(I) sulfide with calcium oxide. How many grams of calcium oxide are needed to produce

OLga [1]

First, 55 g of Hg is 3.65 moles because one mole of Hg has a molar mass of 200.59

Then, the mole ratio of Hg to CaO is 8:4 or 2:1. SO we divide 3.65 by 2 to get 1.82 moles of CaO

This is the same as 102.06 grams because one mole of CaO has a molar mass of 56.0774

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4 0

3 years ago

Describe a composite volcano. Use the following terms in your response: silica-rich, eruption, and crater.

jeka57 [31]

Answer: A composite volcano is the most common type of volcano. They have non-explosion and explosion eruptions. There crater is big, or small. They are also called Stratovolcanoes.

Explanation:

8 0

3 years ago