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3 years ago

What is an atom plz help

Chemistry

2 answers:

Vikki [24]3 years ago

7 0

Answer:

the smallest thing in the world

Explanation:

Akimi4 [234]3 years ago

3 0

Answer:

It is the smallest particle of the elements that exists ob the earth

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What do elements in the same group in the periodic table have in common

Shalnov [3]

Answer:

The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.

Explanation:

8 0

3 years ago

What is the mass of helium atom whose atomic weight is 4.003 g/mol?

tino4ka555 [31]

Answer:

Atoms He (Avogadro’s number) → Moles of He (molar mass of He) → Mass of He

• molar mass of He (from the periodic table) = 4.003 g/mol

• Avogadro’s Number: Avogadro’s number gives us the number of entities present in 1 mole: 6.022 × 1023 He atoms in 1 mole of He

hope this is help full please mark me Brainliest

4 0

3 years ago

A 3.31-g sample of lead nitrate, Pb(NO3)2, molar mass = 331 g/mol, is heated in an evacuated cylinder with a volume of 2.53 L. T

Dahasolnce [82]

Answer:

0.486atm is the pressure of the cylinder

Explanation:

1 mole of Pb(NO₃)₂ descomposes in 4 moles of NO2 and 1 mole of O2. That is 1 mole descomposes in 5 moles of gas.

To find the pressure of the cylinder, we need to find moles of gas produced, and using general gas law we can determine the pressure of the gas:

Moles Pb(NO₃)₂ and moles of gas:

3.31g * (1mol / 331g) = 0.01 moles of Pb(NO₃)₂.

That means moles of gas produced is 0.05 moles.

Pressure of the gas:

Using PV = nRT

P = nRT/V

Where P is pressure (Incognite)

V is volume (2.53L)

R is gas constant (0.082atmL/molK)

T is absolute temperature (300K)

And n are moles of gas (0.05 moles)

P = 0.05mol*0.082atmL/molK*300K / 2.53L

P = 0.486atm is the pressure of the cylinder

3 0

3 years ago

How much heat is required to warm 1.50L of water from 25.0C to 100.0C? (Assume a density of 1.0g/mL for the water.)

Masteriza [31]

Answer: The amount of heat required to warm given amount of water is 470.9 kJ

Explanation:

To calculate the mass of water, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of water = 1 g/mL

Volume of water = 1.50 L = 1500 mL (Conversion factor: 1 L = 1000 mL)

Putting values in above equation, we get:

$1g/mL=\frac{\text{Mass of water}}{1500mL}\\\\\text{Mass of water}=(1g/mL\times 1500mL)=1500g$

To calculate the heat absorbed by the water, we use the equation:

$q=mc\Delta T$

where,

q = heat absorbed

m = mass of water = 1500 g

c = heat capacity of water = 4.186 J/g°C

$\Delta T$ = change in temperature = $T_2-T_1=(100-25)^oC=75^oC$

Putting values in above equation, we get:

$q=1500g\times 4.186J/g^oC\times 75^oC=470925J=470.9kJ$

Hence, the amount of heat required to warm given amount of water is 470.9 kJ

6 0

3 years ago

I’m really bad at science and i need to know how to define it

postnew [5]

It is a column of elements in the periodic table of the chemical elements.

5 0

3 years ago