A solution has the same or different properties to the solute and solvent making it up

Which statements accurately describe Dmitri Mendeleev’s contributions to the development of the periodic table? Check all that a

Varvara68 [4.7K]

Answer:

Mendeleev produced the first orderly arrangement of known elements.

Mendeleev used patterns to predict undiscovered elements.

Explanation:

Mendeleev produced the first orderly arrangement of known elements and used patterns to predict the undiscovered elements.

Those two statments are true.

For the time being there were some 62 known elements. Before Medeleev some schemes to order part of the elements were proposed, but Medeleev showed the relationship between the atomic mass and the properties of the elements (supports second choice). This arrangement is known as the periodic table.

More importantly, Mendeleev predicted correctly the existance and properties of unknown elements, which is his major contribution: he left blanket spaces which where gradually filled when new elements where discovered (this supports the fourth choice).

The first modern chemistry book was written by Antoine Lavoisier (this discards first option).

Mendeleev ordered the elements by increasing mass number (this discards third choice), which was corrected later by the scientist Henry Moseley, who ordered the elements by increasing atomic number (number of protons).

Isotopes were not known by Mendeleev times, so this discards the last option.

8 0

4 years ago

Read 2 more answers

Which of the following is true regarding atomic radius?

Ymorist [56]

attachment/photo please

5 0

4 years ago

Calcium carbonate decomposes when heated to solid calcium oxide and carbon dioxide gas. The balanced equation is: CaCO3(s) → CaO

wlad13 [49]

Answer:

The mass of CaCO3 reacted is 5.00 grams

Explanation:

Step 1 :Data given

Before the reaction, the container, including the CaCO3, had a mass of 24.20 g

After the reaction the container with product had a mass of only 22.00 g because the CO2 gas produced did not remain in the container.

Molar mass of CO2 = 44.01 g/mol

Molar mass CaCO3 = 100.09 g/mol

Step 2: The balanced equation

CaCO3 → CaO + CO2

Step 3: Calculate mass of CO2

Mass of CO2 = 24.20 grams - 22.00 grams

Mass of CO2 = 2.20 grams

Step 4: Calculate moles CO2

Moles CO2 = mass CO2 / molar mass CO2

Moles CO2 = 2.20 grams / 44.01 g/mol

Moles CO2 = 0.0500 moles

Step 5: Calculate moles CaCO3

For 1 mol CaCO3 we'll have 1 mol CaO and 1 mol CO2

For 0.0500 moles CO2 we need 0.0500 moles CaCO3

Step 6: Calculate mass CaCO3

Mass CaCO3 = moles CaCO3 * molar mass CaCO3

Mass CaCO3 = 0.0500 moles * 100.09 g/mol

Mass CaCO3 = 5.00 grams

The mass of CaCO3 reacted is 5.00 grams

8 0

4 years ago

Analyze the following reaction and the given scenarios to discuss the relationship between volume and reaction rate. Determine w

vredina [299]

The second reaction with the volume of 5L will occur faster as compared to the first reaction of volume 10L.

Volume is inversely proportional to the rate of reaction.

As volume increases rate of reaction decreases and as volume decreases rate of reaction increases.

Let's consider a reaction A → B.

r is rate of reaction and K is rate constant, A is the concentration of reaction.

r = k(A)

r is directly proportional to the A.

But the concentration of A is in Moles/liters (i.e. moles per unit volume)

r is inversely proportional to the volume of vessel or chamber.

Hence as volume increases rate of reaction decreases.

For study more about reaction rate refer following link brainly.com/question/19513092.

#SPJ1.

5 0

2 years ago

How many centimeters are in .479 kilometers

trapecia [35]

Answer:

47900 cm

General Formulas and Concepts:

Chemistry

Base 10 Decimal System
Using Dimensional Analysis

Explanation:

Step 1: Define

0.479 km

Step 2: Identify Conversions

1 km = 1000 m

1 m = 100 cm

Step 3: Convert

$0.479 \ km(\frac{1000 \ m}{1 \ km} )(\frac{100 \ cm}{1 \ m} )$ = 47900. cm

Step 4: Check

We are given 3 sig figs. Follow sig fig rules.

47900. cm ≈ 47900 cm

7 0

3 years ago