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4 years ago

Define and describe four properties of elements that display periodicity (show a trend) on the periodic table.

1 answer:

5 0

1) Atomic radius: It increases from left to right in a period
2) Ionic radius: It increases from left to right in a period
3) First ionization energy: It increases from left to right in a period
4) Melting point: Generally decreases from left to right in a period

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What are the characteristics of an extrusive rock

olya-2409 [2.1K]

Extrusive Rocks. Igneous rocks which form by the crystallization of magma at the surface of the Earth are called extrusive rocks. They are characterized by fine-grained textures because their rapid cooling at or near the surface did not provide enough time for large crystals to grow.

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4 years ago

A sample of gas occupies a volume of 64.0 mL . As it expands, it does 137.1 J of work on its surroundings at a constant pressure

stiks02 [169]

Answer : The final volume of the gas is, 34.8 L

Explanation :

Formula used :

$w=p\times (V_2-V_1)$

where,

w = work done = 137.1 J = 35.8 L.atm (1 L.atm = 101.3 J)

p = external pressure = 783 torr = 1.03 atm (1 atm = 760 torr)

$V_2$ = final volume = ?

$V_1$ = initial volume = 64.0 mL = 0.0640 L (1 L = 1000 mL)

Now put all the given values in the above formula, we get:

$35.8L.atm=1.03atm\times (V_2-0.0640L)$

$V_2=34.8L$

Thus, the final volume of the gas is, 34.8 L

5 0

4 years ago

According to the Arrhenius concept, an acid is a substance that ________. Group of answer choices can accept a pair of electrons

Schach [20]

Answer: an increase in the concentration of $H^+$ in aqueous solutions and is capable of donating one or more $H^+$

Explanation:

According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions $(OH^-)$ when dissolved in water and an acid is defined as a substance which donates hydrogen ions $(H^+)$ in water.

According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.

According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.

Thus According to the Arrhenius concept, an acid is a substance that causes an increase in the concentration of $H^+$ in aqueous solutions and is capable of donating one or more $H^+$

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4 years ago

A piston in a heat engine does 500 joules of work, and 1400 joules of heat are added to the system. Determine the change in inte

san4es73 [151]

Answer : The change in internal energy is, 900 Joules.

Solution : Given,

Heat given to the system = +1400 J

Work done by the system = -500 J

Change in internal energy is equal to the sum of heat energy and work done.

Formula used :

$\Delta U=q+w$

where,

$\Delta U$ = change in internal energy

q = heat energy

w = work done

As per question, heat is added to the system that means, q is positive and work done by the system that means, w is negative.

Now put all the given values in the above formula, we get

$\Delta U=(+1400J)+(-500J)=900J$

Therefore, the change in internal energy is 900 J.

The change in internal energy depends on the heat energy and work done. As we will change in the heat energy and work done, then changes will occur in the internal energy. Hence, the energy is conserved.

8 0

3 years ago

What does 3.4225e-8 mean

olasank [31]

Answer:

3.4225 * 10^-8

Explanation:

This is just another way to write a number in scientific notation.

7 0

3 years ago