Reading the Temperature of Thermometers

PLEASE HELP WORTH 100 POINTS !!!!!

Rasek [7]

Answer: Imidogen

Explanation: I just looked it up.

5 0

3 years ago

Read 2 more answers

Determine the pressure change when a volume of gas at 760 mmHg is heated from 30.0 °C to 40.0 °C.

bekas [8.4K]

Answer:

253.33 mmHg

Explanation:

According to Charles' Law,

P₁ / T₁ = P₂ / T₂

P₁T₂ = P₂T₁

P₂ = P₁T₂ / T₁

= 760 x 40 / 30

= 760 x 4/3

= 1013.33 mmHg

Change in Pressure

= 1013.33 - 760

= 253.33 mmHg

5 0

2 years ago

2. From each of the following pairs of atoms, pick the atom that has

Zina [86]

Answer:

a) Na

c) Na

b) Sr

d) Ca

Explanation:

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.

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.

7 0

3 years ago

Which element of the periodic table is named after the moon

Troyanec [42]

Answer:

The answer to your question is Selenium

Explanation:

The origin of the names of the elements comes from different origins

For example

Sanskrit words. 14 elements have roots from this language

Planets, 4 elements took their names from the planets.

Greek, 42 elements took their names from these languages

The name of Selenium comes from the greek that means moon.

8 0

3 years ago

How many total atoms are in 0.290 g of P2O5?

Sliva [168]

There are 8.61 × 10²⁰ atoms in 0.290 g P₂O₅.

Step 1. Convert grams of P₂O₅ to moles of P₂O₅.

$\text{Moles of P}_{2}\text{O}_{5} = \text{0.290 g } \text{P}_{2}\text{O}_{5} \times \frac{\text{1 mol }\text{P}_{2}\text{O}_{5}}{\text{141.94 g }\text{P}_{2}\text{O}_{5}} = \text{0.002 043 mol } \text{P}_{2}\text{O}_{5} \\$

Step 2. Convert moles of P₂O₅ to molecules of P₂O₅.

$\text{Molecules of } \text{P}_{2}\text{O}_{5} = \text{0.002 043 mol } \text{P}_{2}\text{O}_{5} \times \frac{6.022 \times 10^{23}\text{ molecules }\text{P}_{2}\text{O}_{5}}{\text{1 mol } \text{P}_{2}\text{O}_{5}}\\$

$= 1.23 \times10^{21}\text{ molecules } \text{P}_{2}\text{O}_{5}\\$

Step 3. Convert molecules of P₂O₅ to atoms.

There are seven atoms in 1 mol P₂O₅.

∴ $\text{Total atoms} = 1.23\times 10^{21 }\text{ molecules }\text{P}_{2}\text{O}_{5} \times\frac{\text{7 atoms}}{\text{1 molecule }\text{P}_{2}\text{O}_{5}} = 8.61 \times 10^{21}\text{ atoms}\\$

8 0

3 years ago