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3 years ago

What do the elements in each column of the periodic table have in common?

Chemistry

1 answer:

Svetlanka [38]3 years ago

8 0

Answer:

Valency - Number of outermost electrons

Explanation:

Periodic table are generally divided into rows and columns.

Each columns in the periodic table is referred to as groups. Each groups represent the valency of the element. That is, the total number of outermost electrons. Due to the same number of valency, elements in the same group show similar chemical properties.

This means that group 1 elements have a valency of 1 , group 2 elements have a valency of 2.

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What kind of charge does a cation have

Ainat [17]

I believe it has a positive
charge

6 0

3 years ago

Read 2 more answers

The net force on an object that is accelerating at a rate of 4 m/sec is 255 N. What is the mass of the object in kg?

aleksklad [387]

Answer:

Given - acc = 4 m/ s^2

Force = 255 N

To find = mass

Solution -

Using the formula,

$f = m \times a$

255 = Mass × 4

255 /4 = Mass

63.75 = Mass

1 N = kg m/s^2

63.75 kg = Mass

7 0

3 years ago

Calculate the Equilibrium constant Kc at 25 C from the free - energy change for the following reaction . Zn(s) + 2Ag+(aq)<---

FinnZ [79.3K]

Answer: $Kc=1.24*10^5^2$

Explanation: For the given reaction:

$Kc=\frac{[Zn^+^2]}{[Ag^+]^2}$

Concentrations of the ions are not given so we need to think about another way to calculate Kc.

We can calculate the free energy change using the standard cell potential as:

$\Delta G^0=-nFE^0_c_e_l_l$

$E^0_c_e_l_l$ can be calculated using standard reduction potentials.

Standard reduction potential for zinc is -0.76 V and for silver, it is +0.78 V.

$E^0_c_e_l_l$ = $E^0_c_a_t_h_o_d_e+E^0_a_n_o_d_e$

Reduction takes place at anode and oxidation at cathode. As silver is reduced, it is cathode. Zinc is oxidized and so it is anode.

$E^0_c_e_l_l$ = 0.78 V - (-0.76 V)

$E^0_c_e_l_l$ = 0.78 V + 0.76 V

$E^0_c_e_l_l$ = 1.54 V

Value of n is two as two moles of electrons are transferred in the cell reaction F is Faraday constant and its value is 96485 C/mol of electron .

$\Delta G^0=-(2*96485*1.54)$

$\Delta G^0$ = -297173.8 J

Now we can calculate Kc using the formula:

$\Delta G^0=-RTlnKc$

T = 25+273 = 298 K

R = $8.314JK^-^1mol^-^1$

--297173.8 = -(8.314*298)lnKc

297173.8 = 2477.572*lnKc

$lnKc=\frac{297173.8}{2477.572}$

lnKc = 119.946

$Kc=e^1^1^9^.^9^4^6$

$Kc=1.24*10^5^2$

5 0

3 years ago

Rx: Codeine phosphate 30 mg/tsp Tussin syrup 30mL Elixophyllin qs 240 mL Sig: 5mL qid pc hs If 5 mL of Tussin syrup contains 100

kotykmax [81]

Answer:

50 mg.

Explanation:

From the prescription, 240 ml amount is to be prepared containing 30 ml tussin syrup. As the frequency is 5 mL qid, it means 5mL of syrup is to be administered four times daily i.e. 20 mL daily. To calculate the amount of tussin taken daily,

30 mL tussin = X mL of tussin

240 mL solution 20ml solution

⇒ 2.5 mL of tussin

5 ml tussin contains 100mg guafenesin,

So,

⇒ 2.5 ml of tussin contains 100x2.5/5 = 50 mg guaifenesin

4 0

3 years ago

Why are the outer-most electrons the only ones included in the electron dot diagram?

kupik [55]

Answer:

Atoms with 5 or more valence electrons gain electrons forming a negative ion, or anion. why are outermost electrons only ones included in orbital filling diagram? they are the only ones involved in chemical reactions and bonding. ... 2s orbital is farther from the nucleus meaning it has more energy.

Explanation:

8 0

4 years ago