Which of these questions is a scientific question?

A tire at 21°C has a pressure of 0.82 atm. Its temperature decreases to –3.5°C. If there is no volume change in the tire, what i

IRINA_888 [86]

Answer : The pressure after the temperature change is, 0.752 atm

Explanation :

Gay-Lussac's Law : It is defined as the pressure of the gas is directly proportional to the temperature of the gas at constant volume and number of moles.

$P\propto T$

or,

$\frac{P_1}{T_1}=\frac{P_2}{T_2}$

where,

$P_1$ = initial pressure = 0.82 atm

$P_2$ = final pressure = ?

$T_1$ = initial temperature = $21^oC=273+21=294K$

$T_2$ = final temperature = $-3.5^oC=273+(-3.5)=269.5K$

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

$\frac{0.82atm}{294K}=\frac{P_2}{269.5K}$

$P_2=0.752atm$

Thus, the pressure after the temperature change is, 0.752 atm

4 0

4 years ago

The number of electrons in n=1 and n=2 shells of aluminum are

harina [27]

Answer:

n=1 holds two electrons and n=2 holds eight electrons.

Explanation:

Hello

In this case, since the atomic number of aluminum is 13, its electron configuration is:

$Al^{13}: 1s^2,2s^2,2p^6,3s^2,3p^1$

In such a way, we can see that the level n=1 is filled with two electrons since the subshell s is able to hold two electrons and the level n=2 is also filled but with eight electrons as s holds two whereas p holds 6. Moreover, n=3 is holding three electrons.

Best regards.

5 0

3 years ago

Is matter and mass always the same

Anna11 [10]

Matter is a slightly archaic word for something with mass, as in the conservation of matter (which must be paired with the conservation of energy to still hold true. Mass can be converted back and forth between energy, so therefore so can matter. Of course relativistic mass is conserved as it's a function of the energy of an object in that reference frame.

6 0

4 years ago

Read 2 more answers

What reaction might we use to synthesize nickel sulfate,niso4? Write equations for acid base neutralization. Include states in y

il63 [147K]

Answer:

Here's what I get

Explanation:

1. Nickel sulfate

base + acid ⟶ salt + water

NiSO₄ is a salt of the base Ni(OH)₂ and the acid sulfuric acid.

Hydroxides of transition metals are insoluble; most sulfates are soluble.

$\underbrace{\hbox{Ni(OH)$_{2}$(s)}}_{\hbox{base}} + \underbrace{\hbox{H$_{2}$SO$_{4}$(aq)}}_{\hbox{acid}} \longrightarrow \, \underbrace{\hbox{NiSO$_{4}$(aq)}}_{\hbox{salt}} + \underbrace{\hbox{2H$_{2}$O(l)}}_{\hbox{water}}$

2. Carbonate + acid

Most carbonates are insoluble.

They react with acids to form carbonic acid (H₂CO₃), which decomposes into water and carbon dioxide.

$\rm NiCO_{3}(s) + H_{2}SO_{4}(aq) \longrightarrow \, NiSO_{4}(aq) + H_{2}O(l) + CO_{2}(g)$

5 0

3 years ago

(Digestion, Intestine, Bile)is secreted by the liver to help in the breaking down of food particles.

Yuri [45]

Answer:

Bile

Explanation:

Bile is secreted by the liver to help in the breaking down of food particles.

5 0

1 year ago