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2 years ago

How do I tell the number of Valence electrons present in an element just by looking at a periodic table?

Chemistry

1 answer:

zhuklara [117]2 years ago

5 0

Look at the periodic table (Boron has 3) and count up from there

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Solve for b, when c= a/b and a = 5.8 and c= 7.4

vova2212 [387]

Answer:

b= 42.92

Explanation:

5.8 x 7.4 = 42.92

4 0

2 years ago

A metal X from two oxide A and B .3.oogm of A and B contain 0.72 and 1.16g of oxygen respectively.calculate the maases of metal

devlian [24]

Answer:

Explanation:

Firstly, we have to determine the mass of metal X. We can do that by interpreting the first and second statement mathematically.

Metal X can form 2 oxides (A and B).

A + B = 3g

The mass of oxygen in A is 0.72g and the mass of oxygen in B is 1.16g.

The mass of metal X in the two oxides will be the same because it's the same metal.

Thus, we represent the mass of the metal in the two oxides as 2X.

2X + 0.72 + 1.16 = 3

2X + 1.88 = 3

2X = 3 - 1.88

2X = 1.12

X = 0.56

<u>Thus, 0.56 g of the metal combines with 0.72g of oxygen in A and 1.16 g of oxygen in B.</u>

Thus, mass of metal (X) in 1g of oxygen in A is

0.56g ⇒ 0.72g

X ⇒ 1

X = 1 × 0.56/0.72

X = 0.78 g

Hence, 0.78g of the metal will combine with 1g of oxygen for A

Also, mass of metal (X) in 1g of oxygen in B is

0.56g ⇒ 1.16g

X ⇒ 1g

X = 1×0.56/1.16

X = 0.48 g

Thus, 0.48g of the metal will combine with 1g of oxygen for B

6 0

2 years ago

the gas left in an used aerosol can is at a pressure of 103 kPa at 25 degrees celsius if this can be thrown into fire what is th

Rainbow [258]

Hello!

The pressure of the gas when it's temperature reaches 928 °C is 3823,36 kPa

To solve that we need to apply Gay-Lussac's Law. It states that the pressure of a gas when the volume is left constant (like in the case of a sealed container like an aerosol can) is proportional to temperature. This is the relationship derived from this law that we use to solve this problem:

$P2= \frac{P1}{T1}*T2= \frac{103 kPa}{25}*928=3823,36 kPa$

Have a nice day!

5 0

2 years ago

Read 2 more answers

Explain the formation of coke?

solniwko [45]

Answer:

Here is it....

Explanation:

5 0

2 years ago

Please helpppp ASAP !!!!Which phase changes require the addition of energy to happen, which phase changes require the removal of

ziro4ka [17]

Answer:

Evaporation

Explanation:

Evaporation involves a liquid becoming a gas and sublimation is the change of a solid directly to a gas. Phase changes require either the addition of heat energy or subtraction of heat energy .

6 0

2 years ago