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3 years ago

Which sentence about the periodic table of elements is true? *

1 answer:

5 0

Answer: metals are found on the left side of the periodic table

Justification:

A. All elements in period 2 are metals: FALSE.

The period 2 include metals and no metals: Li and Be are metals, while B is a metaloid, and C, N, O, and F are non-metals

B. All elements in group 18 are metals: FALSE.

The elements in group 18 are known as noble gases: He, Ne, Ar, Kr, Xe, Rn, and Og (recently named). All of them are non-metals.

C. Metals are found on the left side of the periodic table. TRUE.

With exception of H.

Alkalyne metals are the group 1 (Li, Na, K, Rb, Cs, and Fr).

Alkalyne-earth metals are the group 2: Be, Mg, Ca, Sr, Ba, and Ra.

Those two are the groups most to the left.

The non-metals are all on the right side of the periodic table.

D. Metals are found on the right side of the periodic table. FALSE.

According to the previous information.

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A typical adult human body contains approximately 2.500 L of blood plasma. How many grams of blood plasma are in the typical adu

kirill115 [55]

Answer:

$m=2.575g$

Explanation:

Hello,

In this case, since the density is defined as the ratio of the mass and volume:

$\rho =\frac{m}{V}$

We can compute the mass of blood as follows:

$m=\rho *V=1.03g/L*2.500L\\\\m=2.575g$

Best regards.

7 0

3 years ago

What mass of sodium chloride (NaCl) forms when 7.5 g of sodium carbonate (Na2CO3) reacts with a dilute solution of hydrochloric

Gre4nikov [31]

The mass of NaCl formed is 8.307 grams

calculation

step 1: write the equation for reaction

Na₂CO₃ + 2HCl → 2 NaCl +CO₂ +H₂O

Step 2: find the moles of Na₂CO₃

moles = mass/molar mass

The molar mass of Na₂CO₃ is = (23 x2) + 12 + ( 16 x3) = 106 g/mol

moles = 7.5 g/106 g/mol =0.071 moles

Step 3: use the mole ratio to determine the mole of NaCl

Na₂CO₃:NaCl is 1:2 therefore the moles of NaCl =0.07 x2 =0.142 moles

Step 4: calculate mass of NaCl

mass= moles x molar mass

the molar mass of NaCl= 23 +35.5 =58.5 g/mol

mass = 0.142 moles x 58.5 g/mol =8.307 grams

8 0

3 years ago

Read 2 more answers

Which of the following statements does not describe what he structure of an atom an atom has a small dense center called nucleus

nikklg [1K]

Answer:

inside the nucleus of an atom are protons and electrons.

5 0

2 years ago

The true absorbance for a 1.0 x 10 −5 M solution is 0.7526. If the percentage stray light for a spectrophotometer is 0.56%, calc

Korvikt [17]

Answer:

The percentage deviation is $\Delta M = 1.87$ %

Explanation:

From the question we are told that

The concentration is of the solution is $C = 1.0*10^{-5} M$

The true absorbance A = 0.7526

The percentage of transmittance due to stray light $z = 0.56$ % $=\frac{0.56}{100} = 0.0056$

Generally Absorbance is mathematically represented as

$A = -log T$

Where T is the percentage of true transmittance

Substituting value

$0.7526 = - log T$

$T = 10^{-0.7526}$

$= 0.177$

$= 17.7$ %

The Apparent absorbance is mathematically represented

$A_p = -log (T +z)$

Substituting values

$A_p = -log(0.177 + 0.0056)$

$= -log(0.1826)$

= 0.7385

The percentage by which apparent absorbance deviates from known absorbance is mathematically evaluated as

$\Delta A = \frac{A -A_p}{A} * \frac{100}{1}$

$= \frac{0.7526 - 0.7385}{0.7526} * \frac{100}{1}$

$\Delta A = 1.87$ %

Since Absorbance varies directly with concentration the percentage deviation of the apparent concentration from know concentration is

$\Delta M = 1.87$ %

6 0

3 years ago

How is inoic and molecular solids differ from each other in solution

Irina18 [472]

Molecular are only between non-metals. Ionic has a higher melting point

4 0

3 years ago

Read 2 more answers