Need help urgently!!

When a scientist is beginning the process what is the key term she or he must ask in order to begin?

ella [17]

Answer:

B- why or how because any scientist deals with matter it's relationships ,properties and its composition which can be inferred from the questions why and how

5 0

3 years ago

Which electron configuration represents the electrons of an atom in an excited state? * 2-3 2-7-1 2-8 2-8-1

Lemur [1.5K]

2-7-1

<h3>Further explanation </h3>

Electrons can move the shell up or down by releasing energy or absorbing energy

Excited electrons show higher electron transfer to the shell by absorbing energy

So it can be concluded that there are 2 conditions:

Ground state is the state of electrons filling shell with the lowest energy levels.

Excited state is the state of electrons which occupies a higher energy level

The state of excited electrons can be seen from the presence of electrons which do not fill the skin completely but fill the skin afterward

2-7-1

From its 8 electron configuration, filling 3 shells, 2 electrons in the firs shell, 7 electrons in the second shell and 1 electron in the third shell

the electrons in the third shell should fill the electrons in the second shell first according to Aufbau rule (lower energy shells)

$\tt 1s^22s^22p^4\rightarrow ground~state\\\\1s^22s^22p^33s^1\rightarrow excited~state$

8 0

3 years ago

compound 1 contains 15.0g of hydrogen and 120.0g oxygen. What is the percent compound of each element?

allsm [11]

Note down the formula below

$\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}$

Mass of the compound

$\\ \sf\longmapsto 15+120=135g$

Mass % of Hydrogen:-

$\\ \sf\longmapsto \dfrac{15}{135}\times 100$

$\\ \sf\longmapsto \dfrac{1}{9}\times 100$

$\\ \sf\longmapsto 11.1\%$

Mass % of Oxygen:-

$\\ \sf\longmapsto \dfrac{120}{135}\times 100$

$\\ \sf\longmapsto \dfrac{8}{9}\times 100$

$\\ \sf\longmapsto 88.9\%$

8 0

3 years ago

Which row probably contains the largest atoms on the periodic table?

svp [43]

The last row going across

7 0

3 years ago

Give three examples, from the lab, where potential energy was converted to kinetic energy.

GREYUIT [131]

Give 3 Examples of where potential energy was converted to knlinetic energy:

Curtain

A ball before moving

An apple from the tree then falling down

When the Curtains are still, we call the that potential energy. If you move the curtains around, that is kinetic energy

The ball is still, that is potential energy. Then the ball is moving, the is kinetic energy

There is a apple ganging from a tree, that is potential energy. That apple is fall, this is kinetic energy

Hope this helps

Don't type or write in the answer, I'm not sure what from the lab means. These are a few potential into kinetic energy I could have think of!

4 0

3 years ago