All categories

2 years ago

17) The elements sodium, magnesium,and silicon

Chemistry

2 answers:

irakobra [83]2 years ago

8 0

A period is a horizontal row and therefore these elements are all in the same period.

If you pull up an image of the periodic table, you will see that all of them are in the same row.

They are not isotopes of each other because an isotope is the same element with a different number of neutrons (example: carbon-12, carbon-13).

Hopefully I helped :)

Murljashka [212]2 years ago

7 0

Answer:

B) are in the same period of elements.

Explanation:

The elements sodium, magnesium, and silicon

A) are isotopes of each other . NO. Isotopes are 2 or more forms of the same element, with a different number of neutrons.

B) are in the same period of elements. YES.

Let's consider the electron configuration of these elements.

₁₁Na 1s² 2s² 2p⁶ 3s¹

₁₂Mg 1s² 2s² 2p⁶ 3s²

₁₄Si 1s² 2s² 2p⁶ 3s² 3p²

Since the valence electrons are in the level 3, they all belong to the third period in the periodic table.

You might be interested in

One lap of an engineered hamster track measures 255 cm. To run 10. meters, how many laps should the hamster run? Report your ans

Maru [420]

Answer:

3.9 laps

Explanation:

Step 1: Given data

Length of the hamster track (L): 255 cm

Total distance to be run (D): 10 m

Step 2: Convert "D" to centimeters

We will use the relationship 1 m = 100 cm.

10 m × (100 cm/1 m) = 1.0 × 10³ cm

Step 3: Calculate the number of laps (n) that the hamster should run

We will use the following expression.

n = D/L

n = 1.0 × 10³ cm/255 cm

n = 3.9

4 0

3 years ago

Balance the following equation: K+ H2O + H2 + KOH

alex41 [277]

Answer:

2K + 2H2O → H2 + 2KOH

Explanation:

Find how many atoms you have on both sides then add 2 to both sides.

Reactant: Products:

K: 1+1=2 K: 1+1=2

H: 2+2=4 H: 3+1=4

O: 1+1=2 O: 1+1=2

Therefore it is balanced. Hope this helps

6 0

2 years ago

PLEASE HELP!!!! WILL MARK BRAINLIEST!!!! A rigid steel container with a volume of 30 L is filled with oxygen to a pressure of 9.

GuDViN [60]

Answer:

12 atm

Explanation:

First, let us convert Celcius into Kelvin: 28.0 °C = 301.15 K and 129.0 °C = 402.15 K

For this question we must employ the Combined Gas Law: $\frac{P_1V_1}{P_2V_2}=\frac{n_1RT_1}{n_2RT_2}$ , where $P_1$ is the initial pressure and $P_2$ is the new pressure.

We know that intitially, P=9 atm, V=30 L, and T=301.15K. From our problem, only temperature and pressure changes, while the number of moles, volume and the gas constant, R, stay the same, so they are irrelevant.

Thus, the filled out Combined Gas Law would be:

$\frac{9 atm}{P_2}$ = $\frac{301.15K}{402.15K}$ , where the volume, moles of gas, and R are cancelled out.

We can manipulate this equation to derive the new pressure. We find that

9atm≈0.74885 $P_2$ .

This means that

$P_2$ ≈9/0.74885≈12 atm

4 0

2 years ago

Isopentyl acetate (C7H14O2), the compound responsible for the scent of bananas, can be produced commercially. Interestingly, bee

lora16 [44]

Answer:

The answer to your question is:

a) 4.64 x 10 ¹⁵ molecules

b) 9.28 x 10 ¹⁵ atoms of O2

Explanation:

MW C7H14O2 = 84 + 14 + 32 = 130 g

a) 130 g of C7H14O2 ---------------- 1 mol of C7H14O2

1 x 10 ⁻⁶ g --------------- x

x = 7.7 x 10 ⁻⁹ mol

1 mol of C7H14O2 -------------- 6 .023 x 10 ²³ molecules

7.7 x 10⁻⁹ mol -------------- x

x = 4.64 x 10¹⁵ molecules

b) 130 g of C7H14O2 ---------------- 1 mol of C7H14O2

1 x 10⁻⁶ C7H14O2 ----------------- x

x = 7.7 x 10 ⁻⁹ mol of C7H14O2

1 mol of C7H14O2 --------------- 2 mol of O2

7.7 x 10 ⁻⁹ ---------------- x

x = 1.54 x 10⁻⁸ mol of O2

1 mol of O2 ----------------- 6.023 x 10 ²³ atoms

1.54 x 10 ⁻⁸ ---------------- x

x = 9.28 x 10 ¹⁵ atoms of O2

8 0

3 years ago

Calculate the number of moles found in 3.045x1024 atoms of helium. PLS HELP

Kisachek [45]

Explanation:

so for this u have to use this equation where

Moles = number of particle/6.02×10^23

= 3.045 × 10^24/6.02×10^23

= 5.0581

write it to 3 S.F so 5.06 moles

4 0

2 years ago