There are two kinds of elements that didn't appear on the periodic table until after 1892. What kinds are they and why do you th

Answer:

The correct options include choice 2, 3, and 6.

Explanation:

Density is identified as the mass of a substance per unit volume occupied by that substance.

The density remains constant for a given substance, regardless of variations in mass and volume hence it is considered an intensive property.

2. 20.2 g of silver in 21.6 mL of water and 12.0 g of silver also in 21.6 mL of water.

3. 15.2 g of copper in 21.6 mL of water and 50.0 g of copper in 23.4 mL of water.

6. 11.2 g of gold in 21.6 mL of water and 14.9 g of gold in 23.4 mL of water.

The same metals in both instances will yield consistent densities due to the fixed density of the metal.

The interaction between calcium carbonate and hydrochloric acid can be represented by the chemical equation,

    CaCO3 + 2HCl --> CaCl2 + H2O + CO2

Calcium carbonate has a molecular weight of 100 g/mol, while hydrochloric acid's molecular weight is 36.45 g/mol. According to the equation, 100 g of calcium carbonate reacts with 72.9 g of hydrochloric acid.

    x = (4 g HCl)(100 g CaCO3 / 72.9 HCl)
      x = 5.49 g

Final result: 5.49 g

Answer:

The solution's absorbance measures 0.21168.

Explanation:

Provided that,

Wavelength = 500 nm

Molar absorptivity = 252 M⁻¹ cm⁻¹

Moles present = 0.00140

Total solution volume = 500.0 mL

Path length = 3.00 mm

We have to determine the molar concentration

Utilizing the formula for molar concentration

Where N = number of moles

V = volume

Input the values into the formula

Next, we will calculate the solution's absorbance

Using the absorbance formula

Substituting values into the equation

Therefore, the absorbance of the solution is 0.21168.

Response:

4

Reasoning:

Answer:

The proportion of the family's overall yearly electricity that is attributed to running both air conditioners over the summer months is = 19.4 %

Explanation:

Monthly average electricity usage = 900 kWh

The family utilizes two window air conditioners to cool their residence during summer for three months.

The electricity usage for a single window-unit air conditioner = 350 kWh

The total power utilized by both window-unit air conditioners = 350(2) = 700 kWh

The total power consumed by two air conditioners for the summer months = 700 (3) = 2100 kWh

The annual total power consumption = 900 (12) = 10800 kWh

The percentage of the family's total annual electricity for operating the air conditioners during summer = = 19.4 %