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2 years ago

How many protons electrons and neutrons are present in the following atoms

Chemistry

2 answers:

grin007 [14]2 years ago

4 0

Answer:the element is potassium

the proton and electron is 19 and the nuetron is 19

Explanation:

Flura [38]2 years ago

3 0

Answer:

The atomic number gives the number of protons 19

p = 19

The atomic mass is the sum of the protons and neutrons

p+n = 39 p = 19

Put p into the equation and solve for n the neutrons

19+n = 39

Subtract 19 from both sides

19-19+n = 39-19

n = 20

The number of electons equal the number of protons in a neutral atom. The positive charge equal to the negative charge. The negative charge is the number of electons. This ion has a charge of +1. So solve for the negative charge.

-19+1 = -18

The negative charge is -18 so

e = 18

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A 100.0 mL sample of a 0.200 M aqueous solution of K2CrO4 was added to 100.0 mL of a 0.100 M aqueous solution of BaCl2. The mixt

stepan [7]

The correct answer is 2.53 g of precipitate, BaCrO4.

5 0

3 years ago

Explain why BH3 is trigonal planar and NH3 is trigonal pyramidal.

Troyanec [42]

Answer:o It is important to realise that mixing will be small unless there are electrons in the 4a1 LUMO, this is why NH3 is pyramidal while BH3 is planar! ... This mixing is very strong and stabilises the 3a1 MO substantially and hence NH3 is trigonal pyramidal and not planar.

Explanation:

3 0

3 years ago

What is the mass of a sample of metal that is heated from 58.8°C to 88.9°C with a

Vadim26 [7]

Answer:

$\boxed {\boxed {\sf 333 \ grams}}$

Explanation:

We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

$Q= mc \Delta T$

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.

ΔT= final temperature - initial temperature

The sample was heated from 58.8 degrees Celsius to 88.9 degrees Celsius.

ΔT= 88.9 °C - 58.8 °C = 30.1 °C

Now we know three variables:

Q= 4500.0 J
c= 0.4494 J/g°C
ΔT = 30.1 °C

Substitute these values into the formula.

$4500.0 \ J = m (0.4494 \ J/g \textdegree C)(30.1 \textdegree C)$

Multiply on the right side of the equation. The units of degrees Celsius cancel.

$4500.0 \ J = m (13.52694 J/g)$

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

$\frac {4500.0 \ J }{13.52694 J/g}= \frac{m (13.52694 J/g)}{13.52694 J/g}$

The units of Joules cancel.

$\frac {4500.0 \ J }{13.52694 J/g}= m$

$332.6694729 \ g =m$

The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

$333 \ g \approx m$

The mass of the sample of metal is approximately 333 grams.

8 0

2 years ago

Which element would you expect to be more metallic? (a) S or Cl (b) In or Al (c) As or Br

Natalija [7]

Explanation:

When we move across a period from left to right then there will occur an increase in electronegativity and also there will occur an increase in non-metallic character of the elements.

As sulfur (S) is a group 16 element and chlorine (Cl) is a group 17 element. Hence, sulfur (S) is more metallic in nature than chlorine.

This means that chlorine (S) is less metallic than chlorine (Cl).

Both indium (I) and aluminium (Al) are group 13 elements. And, when we move down a group then there occur an increase in non-metallic character of the elements. As indium belongs to group 13 and period 5 whereas aluminium belongs to group 13 and period 3.

Therefore, aluminium (Al) is more metallic than indium (In).

Arsenic (Ar) is a group 15 element and bromine (Br) is a group 17 element. Therefore, arsenic is more metallic than bromine.

4 0

3 years ago

When is buying a house better than renting

tester [92]

The answer for that kind of question depends on many things. location, how many people will inhabit the home, whether or not the home is a vacation home or a full time home. etc. P.S. I do not believe that this has anything to do with chemistry

5 0

3 years ago

How many protons electrons and neutrons are present in the following atoms​

How many protons electrons and neutrons are present in the following atoms