Fill the 2 letter bellow h_gs and k

sergij07 [2.7K]

Answer:

True

Explanation:

Heat is a kind of energy.

The kinetic theory relates the heat with the movement of the particles: the more the particles move, the larger the kinetic energy of the system. The kinetic theory states that heat is the kinetic energy of the particles, atoms or molecules, in a substance, that is transferred from a substance at higher temperature to other substance at lower temperature.

Based on that principle, the kinetic theory explains the changes of phases of the substances in terms of the motion of the particles: the hotter an object the faster the particles move, the more energetic the particles are, and they occupy more space. Thus, when a solid is heated, the particles move faster and it can pass to liquid or gaseous state.

7 0

3 years ago

How many grams are there in 3.4 x 10^24 atoms of He?

Lelechka [254]

Given :

Number of He atoms, $n = 3.4\times 10^{24}$ atoms.

To Find :

How many grams are their in given number of He atoms.

Solution :

We know, molecular mass of He is 4 g. It means that their are $6.022 \times 10^{23}$ atoms in 4 g of He.

Let, number of gram He in $3.4\times 10^{24}$ atoms is x , so :

$x = \dfrac{3.4\times 10^{24}}{6.022\times 10^{23}}\times 4\\\\x = $$22.58\ g$

Therefore, grams of He atoms is 22.58 g .

5 0

3 years ago

Iron forms rust, expressed as Fe2O3.

Elina [12.6K]

Answer:

it's C. 159.70 g

Explanation:

hopefully that helps

3 0

2 years ago

The radioactive isotope of lead, Pb-209, decays at a rate proportional to the amount present at time t and has a half-life of 3.

Marina86 [1]

Answer:

Therefore it will take 7.66 hours for 80% of the lead decay.

Explanation:

The differential equation for decay is

$\frac{dA}{dt}= kA$

$\Rightarrow \frac{dA}{A}=kdt$

Integrating both sides

ln A= kt+c₁

$\Rightarrow A= e^{kt+c_1}$

$\Rightarrow A=Ce^{kt}$ [ $e^{c_1}=C$ ]

The initial condition is A(0)= A₀,

$\therefore A_0=Ce^{0.k}$

$\Rightarrow C=A_0$

$\therefore A=A_0e^{kt}$ .........(1)

Given that the $Pb_{209}$ has half life of 3.3 hours.

For half life $A=\frac12 A_0$ putting this in equation (1)

$\frac12A_0=A_0e^{k\times3.3}$

$\Rightarrow ln(\frac12)= 3.3k$ [taking ln both sides, $ln \ e^a=a$ ]

$\Rightarrow k=\frac{ln \frac12}{3.3}$

⇒k= - 0.21

Now A₀= 1 gram, 80%=0.8

and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram

Now putting the value of k,A and A₀in the equation (1)

$\therefore 0.2=1e^{(-0.21)\times t}$

$\Rightarrow e^{-0.21t}=0.2$

$\Rightarrow -0.21t= ln(0. 2)$

$\Rightarrow t= \frac{ln (0.2)}{-0.21}$

⇒ t≈7.66

Therefore it will take 7.66 hours for 80% of the lead decay.

3 0

3 years ago

Describe in your own words, in terms of particle movement and energy, what occurs when a liquid is heated to its boiling point.

Evgen [1.6K]

Particulate movement and energy increases when a liquid is heated to its boiling point. Explanation: When a liquid is heated to its boiling point, the form of the liquid changes. ... The particles with cinematic energy begin to move more randomly. So we can say that the particle movement and the energy grow.

3 0

3 years ago

Fill the 2 letter bellowh_gs and k_sses​

Fill the 2 letter bellowh_gs and k_sses