Answer:
52 da
Step-by-step explanation:
Whenever a question asks you, "How long to reach a certain concentration?" or something similar, you must use the appropriate integrated rate law expression.
The i<em>ntegrated rate law for a first-order reaction </em>is
ln([A₀]/[A] ) = kt
Data:
[A]₀ = 750 mg
[A] = 68 mg
t_ ½ = 15 da
Step 1. Calculate the value of the rate constant.
t_½ = ln2/k Multiply each side by k
kt_½ = ln2 Divide each side by t_½
k = ln2/t_½
= ln2/15
= 0.0462 da⁻¹
Step 2. Calculate the time
ln(750/68) = 0.0462t
ln11.0 = 0.0462t
2.40 = 0.0462t Divide each side by 0.0462
t = 52 da
Answer:
False
Explanation:
It is important to give exact measurements.
Copper is a mineral and an element essential to our everyday lives. It is a major industrial metal because of its high ductility, malleability, thermal and electrical conductivity and resistance to corrosion. It is an essential nutrient in our daily diet. And, its antimicrobial property is becoming increasingly important to the prevention of infection. It ranks third after iron and aluminum in terms of quantities consumed in the USA.
John Dalton's original atomic theory contained the following key ideas and the incorrect one is that elements are made of tiny indivisible particles called atoms and is denoted as option A.
<h3>What is Atom?</h3>
This is defined as the smallest unit of matter which forms a chemical element and Dalton proposed that it was indivisible which was later proved wrong.
It was later discovered that atom is made up of sub atomic particles such as proton, electron and neutron. This was therefore the reason why option A was chosen as the most appropriate choice.
Read more about Atom here brainly.com/question/6258301
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The options include:
A. elements are made of tiny indivisible particles called atoms
B. Atoms are unchanged in chemical reaction
C. Atoms can join together in whole number ratios to form compounds.
D. The atoms of each element are unique