In which situation is an object accelerating?

Which activity is an example of chemical change?

frutty [35]

An old penny rusting, remember you can’t undo a chemical change

3 0

3 years ago

The table compares some characteristics of two atoms.

Mademuasel [1]

Answer:

Explanation:

Atom X,

Neutron num = 4, Mass num = 7

Therefore, proton number = Mass num - Neutron num

= 7 - 4

= 3

Atom Y,

Neutron num = 5, Mass num = 9

Therefore, proton number = Mass num - Neutron num

= 9 - 5

= 4

1) False. Atom X belongs to group 3 while atom Y belongs to group 4

2) False. Atom X is in a column on the left of Atom Y

3) True. Atom X and atom Y belong to the same period two on the periodic table

4) Fasle. Atom X and Y are not isotopes because they do not have the same atomic number.

Isotopy is a phenomenon whereby atom of same element have same atomic number but different mass number

4 0

3 years ago

The electron configuration that belongs to the atom with the lowest first ionization energy is?

sasho [114]

The electron configuration that belongs to the atom with the lowest first ionization energy is francium.

<h3>What is ionization energy? </h3>

Ionization energy is defined as the minimum amount of energy required to remove the most loosely electron present in outermost shell.

<h3>Ionization energy across period</h3>

Ionization energy increase as we move from left to right in the period. This can be explained as when we move from left to right along period new electron is added to the same shell which increase the nuclear charge. Hence results int he decrease in size. Due to this decrease in size more energy is required to remove electron from outermost shell.

<h3>Ionization energy along group</h3>

Ionization energy decrease as we move from top to bottom along group. This can be explained as we move from top to bottom new electron is added to new shell. Due to addition of new shell the size of atom increases which results in the decrease in the nuclear charge. Due to this less amount of energy is needed to remove an electron.

Thus, we concluded that the electron configuration that belongs to the atom with the lowest first ionization energy is francium.

learn more about ionization energy:

brainly.com/question/1602374

#SPJ4

4 0

1 year ago

What is the predicted change in the boiling point of water when 1.50 g of

dezoksy [38]

Answer:

0.00735°C

Explanation:

By seeing the question, we can see the elevation in boiling point with addition of BaCl₂ in water

⠀

$\textsf {While} \: \sf {\Delta T_b} \: \textsf{expression is used} \\ \textsf {for elevation of boiling point}$

⠀

The elevation in boiling point is a phenomenon in which there is increase in boiling point in solution, when the particular type of solute is added to pure solvent.

⠀

$\sf \large \underline{The \: formula \: to \: be \: used \: in \: this \: question \: is} \\ \boxed{T_b = i \times K_b \times m}$

⠀

Where 'i' is van't hoff factor which represents the ratio of observed osmotic pressure and the value to be expected.

and 'i' is 3 (as given in the question)

⠀

'Kb' is molal boiling point constant. And it's value is 0.51°C/mol(given in question)

⠀

'm' represent the molality of solution. Molatity is no. of moles of solution present in 1kg of solution.

⠀

To find molality, we have to divide no. of moles of solute by weight of solution

⠀

While first we need to no. of moles

$\sf \implies no. \: of \: moles = \frac{weight \: of \: solute}{molar \: mass \: of \: solute} \\ \\ \implies \sf no. \: of \: moles = \frac{1.5}{208.23} \\ \\ \sf \implies no. \: of \: moles = 0.0072$

⠀

Now, we will find molality

⠀

$\sf \hookrightarrow molality = \frac{no.\: of \: moles}{weight \: of \: solution} \\ \\ \sf \hookrightarrow molality = \frac{0.072}{1.5} \\ \\ \sf \hookrightarrow molality = 0.048 \: mol {kg}^{ - 1}$