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3 years ago

What are groups 1, 2, and 3 examples of on the periodic table? A. Nonmetals B. Metals C. Noble gases D. Metalloids

Chemistry

2 answers:

crimeas [40]3 years ago

8 0

They are examples of B. Metals on the periodic table.

tankabanditka [31]3 years ago

3 0

The correct answer is:

Metals

They are all alkali and transition metals

Explanation:

The periodic table includes elements clustered into groups with comparable properties. Alkali metals are reactive, soft metals with low densities. Transition metals are unreactive metals that have many have common uses. Halogens are reactive non-metals that form glowing vapors.

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which of the following results when iron and oxygen react? 1.fe2o3 corrodes 2.hydrated iron forms 3.iron oxide forms 4.a shiny m

weeeeeb [17]

It should be 4, a shiny metal forms

3 0

3 years ago

A gaseous mixture composed of 20% CH4, 30% C2H4, 35% C2H2, and 15% C2H20. What is the average molecular weight of the mixture? a

Semenov [28]

Answer: The correct answer is Option d.

Explanation:

We are given:

Mass percentage of $CH_4$ = 20 %

So, mole fraction of $CH_4$ = 0.2

Mass percentage of $C_2H_4$ = 30 %

So, mole fraction of $C_2H_4$ = 0.3

Mass percentage of $C_2H_2$ = 35 %

So, mole fraction of $C_2H_2$ = 0.35

Mass percentage of $C_2H_2O$ = 15 %

So, mole fraction of $C_2H_2O$ = 0.15

We know that:

Molar mass of $CH_4$ = 16 g/mol

Molar mass of $C_2H_4$ = 28 g/mol

Molar mass of $C_2H_2$ = 26 g/mol

Molar mass of $C_2H_2O$ = 48 g/mol

To calculate the average molecular mass of the mixture, we use the equation:

$\text{Average molecular weight of mixture}=\frac{_{i=1}^n\sum{\chi_im_i}}{n_i}$

where,

$\chi_i$ = mole fractions of i-th species

$m_i$ = molar masses of i-th species

$n_i$ = number of observations

Putting values in above equation:

$\text{Average molecular weight}=\frac{(\chi_{CH_4}\times M_{CH_4})+(\chi_{C_2H_4}\times M_{C_2H_4})+(\chi_{C_2H_2}\times M_{C_2H_2})+(\chi_{C_2H_2O}\times M_{C_2H_2O})}{4}$

$\text{Average molecular weight of mixture}=\frac{(0.20\times 16)+(0.30\times 28)+(0.35\times 26)+(0.15\times 42)}{4}\\\\\text{Average molecular weight of mixture}=6.75$

Hence, the correct answer is Option d.

3 0

3 years ago

What is the volume of 0.80 grams of O2 gas at STP? (5 points) Group of answer choices 0.59 liters 0.56 liters 0.50 liters 0.47 l

Anarel [89]

Answer:

0.56 liters

Explanation:

First we convert 0.80 grams of O₂ into moles, using its molar mass:

0.80 g ÷ 32 g/mol = 0.025 mol

At STP, 1 mol of any given mass occupies 22.4 L. With that information in mind we calculate the volume that 0.025 moles of O₂ gas would occupy:

0.025 mol * 22.4 L/mol = 0.56 L

Thus the answer is 0.56 liters.

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3 years ago

What is the difference between a contractor and a starter

Lunna [17]

"A contactor is a electrically controlled switch which uses an electromagnetic coil to pull in the contacts.”

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4 years ago

Reactions rates for reactions occurring in solution can be increased by increasing the concentration of the solution. With gases

LUCKY_DIMON [66]

"Increase Pressure " is the right answer. if you need help , let me know

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3 years ago