According to the ph scale, which substance is the most basic?

scandium47 has a half-life of 35s. suppose you have a 45g sample of scadium 47 how much of the sample remains unchanged after 14

Mars2501 [29]

The much of the sample that would remain unchanged after 140 seconds is 2.813 g

Explanation

Half life is time taken for the quantity to reduce to half its original value.

if the half life for Scandium is 35 sec, then the number of half life in 140 seconds

=140 sec/ 35 s = 4 half life

Therefore 45 g after first half life = 45 x1/2 =22.5 g

22.5 g after second half life = 22.5 x 1/2 =11.25 g

11.25 g after third half life = 11.25 x 1/2 = 5.625 g

5.625 after fourth half life = 5.625 x 1/2 = 2.813

therefore 2.813 g of Scandium 47 remains unchanged.

4 0

2 years ago

describe the independent and dependent variables in this experiment then describe the other variables that need to be controlled

uranmaximum [27]

independent variable is being controlled and the dependent variable is being tested and being easured in a scientific experiment

3 0

2 years ago

If a block has the mass of 15.00 grams and measurements of 5.00cm by 3.00cm by 2.00cm what is the volume of the block?

Natalija [7]

Answer:

Volume = 30cm³

Explanation:

A block is a geometrical figure and its volume, -look at the figure-, follows the equation:

Volume = Width*Length*Height

As the measurements of the block are 5.00cm, 3.00cm and 2.00cm, the volume is:

Volume = 5.00cm*2.00cm*3.00cm

<h3>Volume = 30cm³</h3>

3 0

2 years ago

Question 3 (1 point)

antoniya [11.8K]

An electrochemical process involves any process that has to do with the transfer of elecrons.

<h3>What is an elecrochemical process?</h3>

An electrochemical process involves any process that has to do with the transfer of elecrons. These process include redo reactionand electron transport chains.

It is a true statement that the actiivity series helps to detect the products in a reaction because a metal that is lower in the series is always displaced by a metal that is higher in the series.

Learn more about electrochemical processess: brainly.com/question/12034258

6 0

2 years ago

How many moles of k3po4 can be formed when 4.4 moles of h3po4 react with 3.8 moles of koh? h3po4 + koh yields h2o + k3po4 be sur

schepotkina [342]

the balanced chemical equation for the reaction is as follows

H₃PO₄ + 3KOH ---> K₃PO₄ + 3H₂O

stoichiometry of H₃PO₄ to KOH is 1:3

first we have to find which the limiiting reactant is

as the amount of product formed depends on the amount of limiting reactant present

number of H₃PO₄ moles reacted - 4.4 mol

if H₃PO₄ is the limiting reactant

1 mol of H₃PO₄ reacts with 3 mol of KOH

then 4.4 mol of H₃PO₄ reacts with - 3 x 4.4 mol = 13.2 mol of KOH

but only 3.8 mol of KOH is present

therefore KOH is the limiting reactant

stoichiometry of KOH to K₃PO₄ is 3:1

number of KOH moles reacted - 3.8 mol

therefore number of K₃PO₄ formed = number of KOH moles reacted / 3

= 3.8 mol / 3 = 1.3 mol

answer is 1.3 mol of K₃PO₄

3 0

3 years ago