HEY Plzzzzzzzzzzz HELP ILL GIVE BRAINLIEST ASAPPPPPPPPPPP

An element that has 2 core electrons and 3 valence electrons

gavmur [86]

Answer:

Boron

Explanation:

You can find this by looking at the number of protons in Boron, 5.

Then calculate how many electrons you are given, in this case the 2 core plus the 3 valence equal 5 total electrons

Neutral elements have the same number of protons and electrons, so your answer would be the element with 5 electrons, Boron.

You can also know this by using electron configuration. Since you kow there are 5 electrons then you can use EC to find out where your element is. In this case it is: 1s2 2s2 2p1

6 0

3 years ago

Match these items.

dolphi86 [110]

g - Measurement of Mass

m² - Measurement of Area

m³ - Measurement of Volume

km- Measurement of Length

5 0

3 years ago

The atomic mass can be smaller than the atomic number

madreJ [45]

That answer is true. bleh bleh bleh bleh

8 0

3 years ago

The nonvolatile, nonelectrolyte estrogen (estradiol), C18H24O2 (272.40 g/mol), is soluble in chloroform CHCl3.

Artist 52 [7]

<u>Answer:</u> The molarity of solution is 0.274 M and the osmotic pressure of the solution is 6.70 atm

<u>Explanation:</u>

To calculate the molarity of the solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

We are given:

Given mass of estrogen = 13.5 g

Molar mass of estrogen = 272.40 g/mol

Volume of solution = 181 mL

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{13.5\times 1000}{272.40\times 181}\\\\\text{Molarity of solution}=0.274M$

Hence, the molarity of solution is 0.274 M

To calculate the osmotic pressure of the solution, we use the equation:

$\pi=iMRT$

where,

$\pi$ = osmotic pressure of the solution = ?

i = Van't hoff factor = 1 (for non-electrolytes)

M = molarity of solute = 0.274 M

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the solution = 298 K

Putting values in above equation, we get:

$\pi=1\times 0.274mol/L\times 0.0821\text{ L.atm }mol^{-1}K^{-1}\times 298K\\\\\pi=6.70atm$

Hence, the osmotic pressure of the solution is 6.70 atm

8 0

3 years ago

2HgCl2(aq) + C2O42–(aq) → 2Cl–(aq) +2CO2(g) + Hg2Cl2(s)

alexgriva [62]

Explanation:

Expression for rate of the given reaction is as follows.

Rate = k[HgCl_{2}]x [C_{2}O^{2-}_{4}]y[/tex]

Therefore, the reaction equations by putting the given values will be as follows.

$1.8 \times 10^{-5} = k[0.105]x [0.15]y$ ............. (1)

$7.2 \times 10^{-5} = k [0.105]x [0.30]y$ ........... (2)

$3.6 \times 10^{-5} = k [0.0525]x [0.30]y$ ............ (3)

Now, solving equations (1) and (2) we get the value of y = 2. Therefore, by solving equation (2) and (3) we get the value of x = 1.

Therefore, expression for rate of the reaction is as follows.

Rate = $k[HgCl_{2}]x [C_{2}O^{2-}_{4}]y$

Rate = $k [HgCl2]1 [C_{2}O^{-2}_{4}]2$

Hence, total order = 1 + 2 = 3

According to equation (1),

$1.8 \times 10^{-5} = k[0.105]x [0.15]y$

$1.8 \times 10^{-5} = k [0.105]1 [0.15]2$

k = $7.6 \times 10^{-3} M^{-2} min^{-1}$

Thus, we can conclude that rate constant for the given reaction is $7.6 \times 10^{-3} M^{-2} min^{-1}$ .

8 0

3 years ago