The element that is shiny in appearance quite dense and liquid at room temperature is

hich of the following changes always leads to an increase in the rate constant for a reaction: Decreasing the temperature Decrea

GrogVix [38]

Answer:

Only one—(i), or (ii), or (iii)—increases the reaction rate.

Explanation:

Which of the following changes always leads to an increase in the rate constant for a reaction?

Decreasing the temperature. NO. A lower temperature leads to a slower reaction because the molecules have less energy to react.
Decreasing the activation energy. YES. According to the Arrhenius equation, the lower the activation energy, the higher the rate constant.
Making the value of ΔE more negative. NO. A more negative ΔE means a reaction is more spontaneous but not faster.

4 0

4 years ago

A nonmetal

mars1129 [50]

$^{16}_{\phantom{1}8}\text{O}$ .

Oxygen-16 is the atom in question.

Atomic number: 8.
Mass number: 16.

<h3>Explanation</h3>

The superscript of the ion says "2-". That means that the ion here carries a charge of -2.

The charge is negative, meaning that there are more electrons (which are negative) than protons (which are positive) in that ion.
The size of the charge is 2. There are two more electrons than protons in that ion.

There are 10 electrons in total in that ion. There are two more electrons than protons. That means that there are 10 - 2 = 8 protons in that ion.

The atomic number of an atom is the same as its number of protons. The atomic number of X is 8.

The atomic number determines the element. Atomic number 8 is oxygen. Thus element X is oxygen.

Mass number is the sum of number of protons and neutrons in an atom. 8 + 8 = 16 for this atom.

5 0

3 years ago

Which are the hybrid orbitals of the carbon atoms in the following molecules? (a) H3C―CH3 sp sp2 sp3 (b) H3C―CH═CH2 sp sp2 sp3 (

kherson [118]

Answer:

(a) sp³ sp³

H₃C - CH₃

(b) sp³ sp²

H₃C - CH = CH₂

sp²

(c) sp³ sp

H₃C - C ≡ C - CH₂OH

sp sp³

(d) sp³ sp²

H₃C - CH=O

Explanation:

Alkanes or the carbons with all the single bonds are sp³ hybridized.

Alkenes or the carbons with double bond(s) are sp² hybridized.

Alkynes or the carbons with triple bond are sp hybridized.

Considering:

(a) H₃C-CH₃ , Both the carbons are bonded by single bond so both the carbons are sp³ hybridized.

Hence,

sp³ sp³

H₃C - CH₃

(b) H₃C-CH=CH₂ , The carbon of the methyl group is sp³ hybridized as it is boned via single bonds. The rest 2 carbons are sp² hybridized because they are bonded by double bond.

Hence,

sp³ sp²

H₃C - CH = CH₂

sp²

(c) H₃C-C≡C-CH₂OH , The carbons of the methyl group and alcoholic group are sp³ hybridized as it is boned via single bonds. The rest 2 carbons are sp hybridized because they are bonded by triple bond.

Hence,

sp³ sp

H₃C - C ≡ C - CH₂OH

sp sp³

(d)CH₃CH=O, The carbon of the methyl group is sp³ hybridized as it is boned via single bonds. The other carbon is sp² hybridized because it is bonded by double bond to oxygen.

Hence,

sp³ sp²

H₃C - CH=O

8 0

3 years ago

The salts you tested were held together by ionic bonds. The compounds were made of two types of ions, positive and negative, tha

vladimir1956 [14]

Answer:

A an ionic compound that completely dissolves in water, forming many ions

Explanati

5 0

3 years ago

Read 2 more answers

A bicycle rider is applying a force of 20 N while heading south against a wind blowing from the south with a force of 5 N

Alenkasestr [34]

Answer:

the bike will go down 5 N

7 0

3 years ago