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4 years ago

Which of the following is a true statement regarding the periodic table?

1 answer:

7 0

D except for the transition metals copper iron tantalum etc they have different oxidation states so arent fixed shells but all main group elements are grouped by the valence electrons sodium potassium lithium alkali column 1 valence electron highly reactive.

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What is the name for a substance made of billions of oppositely charged ions joined together?

bija089 [108]

Answer:

Ionic substance

Explanation:

An ionic substance is formed when oppositely charged ions link up to form an infinitely large lattice structure that can only be described in terms of unit cells.

Ionic substances may consist of billions of oppositely charged ions. Ionic substances are hard, have high melting and boiling points and do not conduct electricity in the solid state because the ions are not free in the solid state.

However, in solution or molten state, the substance conducts electricity since the ions which are the charge carriers are now mobile.

8 0

3 years ago

What is the electron configuration for a calcium atom? 1s2, 2s2, 2p6, 3s2, 3p6, 4s2 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 2s2, 2s2, 2p6,

Zarrin [17]

1s2,2s2, 2p6, 3s2,3p6,4s2

8 0

3 years ago

Read 2 more answers

Density is 6g/mL and volume is 40 mL what is the mass

myrzilka [38]

Answer:

240g

Explanation:

Using the equation m=pV, where m=mass, p=density, and V=Volume

m=(6)(40)=240

m=240

8 0

3 years ago

A student is investigating the pH of a substance. The pH of the unknown substance is 5.4. Which of the following substances is t

zimovet [89]

Answer:

Substance A.

Explanation:

pH is a measure of the concentration of H₃O⁺ ions in a solution.

It is defined as:

$pH=\log \dfrac{1}{[H_3O^+]}=-\log [H_3O^+]$

For the given substances

Sustance [H₃O⁺] pH = - log [H₃O⁺]

A 4×10⁻⁶ -log (4×10⁻⁶) = 5.4 ← answer

B 6×10⁻⁷ -log (6×10⁻⁷) = 6.2

C error - - - - - -

D 1.3×10⁻¹ -log (1.3×10⁻¹) = 0.89

Thus, the unknown substace most likely is A.

3 0

3 years ago

Identitfy the types of reaction:

Vera_Pavlovna [14]

Answer:

C2H5OH + Na = C2H5ONa + H2 - Single replacement reaction

AgCl + HNO3 = AgNO3 + HC - Double replacement reaction

N2 + H2 = NH3 - Combination reaction

MgCO3 = MgO + CO2 - Decomposition reaction

Explanation:

Single replacement reaction - The type of reaction in which one strong ion replaces the weak ion from the solution.

For example: C2H5OH + Na = C2H5ONa + H2

Double replacement reaction - The reaction in which two compounds in a solution reacts by interchanging their ions and forms a new product.

For example: AgCl + HNO3 = AgNO3 + HCl

Combination reaction - The type of reaction in which two or more compounds combine together to form a single compound.

For example: N2 + H2 = NH3

Decomposition reaction - The type of reaction in which only one compounds break down into two or more new compounds.

For example: MgCO3 = MgO + CO2

Hence, the correct answer is:

C2H5OH + Na = C2H5ONa + H2 - Single replacement reaction

AgCl + HNO3 = AgNO3 + HC - Double replacement reaction

N2 + H2 = NH3 - Combination reaction

MgCO3 = MgO + CO2 - Decomposition reaction

7 0

4 years ago