Number of significant figures will be 1.
Given:
weight of acetylsalicylic acid = 0. 4g
Significant figures are the digits of value which carry meaning towards the resolution of the measurement. They are also called significant figures in chemistry. All the experimental measurements have some kind of uncertainty associated with them.
When we convert 0.4g acetylsalicylic acid to mg we get value 400mg
when we convert 400mg to gram we get value of 0.4 gram
Since 0 before a decimal is not significant so there is only one significant figure that is 4.
<h3>How do you determine the number of significant figures?</h3>
- The zero to the left of a decimal value less than one is meaningless.
- All trailing zeros that are placeholders are meaningless.
- The presence of zeros between non-zero numbers is significant.
- Non-zero numbers are all significant.
- If a number contains more digits than the desired number of significant digits, it is rounded.
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It's an important story for a variety of reasons, and it comes at a time when people are looking to Hollywood more than ever to tell stories that represent them. Hidden Figures is that movie for many, and it's critical that everyone sees these women in action. This is why. This film tells a story that you've probably never heard before.
Learn more about Significant figure here:
<u><em>brainly.com/question/24491627</em></u>
#SPJ4
Answer: 15.1 grams
Given reaction:
Na2CO3 + Ca(OH)2 → 2NaOH + CaCO3
Mass of Na2CO3 = 20.0 g
Molar mass of Na2CO3 = 105.985 g/mol
# moles of Na2CO3 = 20/105.985 = 0.1887 moles
Based on the reaction stoichiometry: 1 mole of Na2CO3 produces 2 moles of NaOH
# moles of NaOH produced = 0.1887*2 = 0.3774 moles
Molar mass of NaOH = 22.989 + 15.999 + 1.008 = 39.996 g/mol
Mass of NaOH produced = 0.3774*39.996 = 15.09 grams
Explanation:
We can define atomic mass the total of number of protons and number of neutrons in an atom or isotope.
<span>So when an isotope of yttrium has 39 protons and 59 neutrons, its atomic mass is equal to;
number of protons + number of neutrons = 39 + 59 = 98</span>
The correct answer is c, it’s evaporating there for it’s a chemical change
Answer:
Henry Moseley
Explanation:
Dmitry Mendeleef and Lothar Meyer proposed a periodic table based on the atomic mass.
They stated a periodic law expressed as "chemical properties of elements are a periodic function of their atomic weights".
But, Henry Moseley in 1900s re-stated periodic law by changing the basis of the law from atomic weight to atomic number.
The present periodic law is stated as "the properties of elements are a periodic function of their atomic number".
