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3 years ago

Help meee pleaseeeee

Chemistry

1 answer:

tatiyna3 years ago

7 0

Answer:

see explanation

Explanation:

Using the periodic table, look at the top of each column => These are group numbers ... Typically (for american tables) the numbers are divided into A-Groups and B-Groups... For this post, you need to focus on the A-Groups, or 'Main Group Elements'... Now, the numbers also represent the number of valence (outer shell) electrons in the elements listed below that number. For example, under Group IA, all elements ( H, Li, Na, K, Rb, Cs & F) all have one (1) outer shell electron. All elements under IIA have two outer shell electrons, IIIA, 3 outer shell electrons and so on. The exception is Helium (He) which has only 2 outer shell electrons and is typically listed under Group VIIIA.

So ...

X· => H, Li & Na

X: => He(noble gas exception), Be & Mg

·X: => B & Al

:X: => C & Si

X(5 dots) => N

X(6 dots) => O

X(7 dots) => F & I

X(8 dots) => Ne

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makkiz [27]

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4 0

2 years ago

Read 2 more answers

Calculate the mass of H2OH2O produced by metabolism of 2.4 kgkg of fat, assuming the fat consists entirely of tristearin (C57H11

otez555 [7]

Answer:

2,669.58 grams of water will be produced by metabolism of 2.4 kilogram of fat.

Explanation:

$2C_{57}H_{110}O_6+163O_2\rightarrow 114CO_2+110H_2O$

Mass of fat = 2.4 kg = 2.4 × 1000 g = 2400 g

1 kg = 1000 g

Molar mass of fat = M

M = 57 × 12 g/mol + 110 × 1 g/mol+ 6 × 16 g/mol = 890 g/mol[/tex]

Moles of fat = $\frac{2400 g}{890 g/mol}=2.6966 mol$

According to reaction , 2 moles of fat gives 110 moles of water. Then 2.6966 moles of fat will give ;

$\frac{110}{2}\times 2.6966 mol=148.31 mol$ of water

Mass of 148.31 moles of water ;

148.31 mol × 18 g/mol = 2,669.58 g

2,669.58 grams of water will be produced by metabolism of 2.4 kilogram of fat.

8 0

2 years ago

How to calculate the frequency of an ion

sergij07 [2.7K]

solution:

You need to find the frequency, and they have already given you the wavelength. And since you already know the speed of light, you can use formula (2) to answer this problem. Remember to convert the nano meters to meters because the speed of light is in meters. $(1 nm = 1.0 x 10^{-9} m)$

$v=c\lambda \\v= (3.00 \times 10^8 m/s)/(6.9\times 10^-7 m) \\v = 4.35 \times 10^{14} s^{-1}$

8 0

3 years ago

. Given the following pOH's, calculate the pH for the solution:

ryzh [129]

Answer:

a) pH = 9.82 b) pH = 1.65

a) pOH = 7.8 b) pOH = 4.45

Explanation:

pOH + pH = 14 for all of these solutions.

3 0

3 years ago

The statement "electrons have a negative charge" is true. Select the correct evidence scientist have that proves this statement

Kryger [21]

The question is incomplete but i will try to offer as much help as i can.

Answer:

See explanation

Explanation:

The electron was discovered by J.J Thompson. His model of the atom was called the plum-pudding model of the atom.

He discovered that cathode rays being negatively charged particles were deflected by a magnet in just the same way as moving, negative electrically charged particles.

Similarly, in an electric field, they are deflected towards the positive plate of the electrostatic field which shows that they are negatively charged.

3 0

3 years ago