All categories

3 years ago

What statement about models of isotopes below is accurate?

Chemistry

1 answer:

ryzh [129]3 years ago

4 0

Answer : The correct option is (C) each picture represents an isotope of lithium because they each have 3 protons.

Explanation :

Isotope : It is defined as the element that have the same number of protons but have the different number of neutrons of each of the atom.

As in the given picture, the number of protons are same but number of neutrons are different.

As we know that atomic number is either equal to number of protons or electrons for neutral atom.

The number of protons in the given picture are 3.

So, the element will be lithium with atomic number 3 and all are the isotopes of lithium.

Hence, the correct option is (C) each picture represents an isotope of lithium because they each have 3 protons.

You might be interested in

Consider the three statements below. Which numbered response contains all the statements that are true and no false statements?

vladimir1956 [14]

Answer:

a) I, II, and III

Explanation:

For the first statement;

Solvation, is the process of attraction and association of molecules of a solvent with molecules or ions of a solute. if the solvent is water, we call this process hydration.

This means the statement is TRUE.

For the second statement;

The negatively-charged side of the water molecules are attracted to positively-charged ions. In the case of water, the oxygen end is the negatively charged side of water. This means the statement is TRUE.

For the third statement;

The positively-charged side of the water molecules are attracted to the negatively-charged chloride ions. In the case of water, the hydrogen end is the positively charged side of water. This means the statement is TRUE.

Going through the options, we can tell that the correct option is option A.

6 0

3 years ago

What is the mass percent of oxygen in sodium bicarbonate (NaHCO3)?

Alenkasestr [34]

The answer is 57.14%.

First we need to calculate molar mass of NaHCO3. Molar mass is mass of 1 mole of a substance. It is the sum of relative atomic masses, which are masses of atoms of the elements.

Relative atomic mass of Na is 22.99 g
Relative atomic mass of H is 1 g
Relative atomic mass of C is 12.01 g
Relative atomic mass of O is 16 g.

Molar mass of NaHCO3 is:
22.99 g + 1 g + 12.01 g + 3 · 16 g = 84 g

Now, mass of oxygen in NaHCO3 is:
3 · 16 g = 48 g

mass percent of oxygen in NaHCO3:
48 g ÷ 84 g · 100% = 57.14%

Therefore, the mass percent of oxygen in sodium bicarbonate is 57.14%.

8 0

3 years ago

In Philip’s French class, the students are learning how to pronounce closed vowels and open vowels. The students are most likely

Sladkaya [172]

Answer:

It sounds like they are studying French phonemes

Explanations:

I just learned this.

7 0

3 years ago

Read 2 more answers

The half life for the first order conversion of A to B is 56.6 hours. How long does it take for the concentration of A to decrea

sveta [45]

Answer:

It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.

Explanation:

A → B

Initial concentration of the reactant = x

Final concentration of reactant = 10% of x = 0.1 x

Time taken by the sample, t = ?

Formula used :

$A=A_o\times e^{-\lambda t}\\\\\lambda =\frac{0.693}{t_{\frac{1}{2}}}$

where,

$A_o$ = initial concentration of reactant

A = concentration of reactant left after the time, (t)

$t_{\frac{1}{2}}$ = half life of the first order conversion = 56.6 hour

$\lambda$ = rate constant

$A=A_o\times e^{-(\frac{0.693}{t_{1/2}})\times t}$

Now put all the given values in this formula, we get

$0.1x=x\times e^{-(\frac{0.693}{56.6 hour})\times t}$

t = 188.06 hour

It will take 188.06 hours for the concentration of A to decrease 10.0% of its original concentration.

4 0

3 years ago

Which part of the atom is directly involved in chemical changes? A. the electron B. the energy levels C. the nucleus D. the char

7nadin3 [17]

The part of the atom that is involved in chemical changes is A. electron. The electrons that are in the most outer shells are called valence electrons which are easily removed or shared to form bonds. Valence electrons are related to the number of valence electrons

8 0

3 years ago