1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Contact [7]
3 years ago
10

Julie finds a snail on the sidewalk and wants to know whether or not the snail moves throughout the day. She places a single mar

k on the sidewalk next to the snail.
What will Julie use the mark for initially?

determining how fast the snail moves
acting as a standard unit of measure
determining the displacement of the snail
acting as a reference point for detecting motion
Chemistry
2 answers:
dexar [7]3 years ago
8 0

Answer:

b-acting as a standard unit of measure

Explanation:

Fofino [41]3 years ago
5 0

Answer:

b

Explanation:

You might be interested in
Please give me solved answer pic its really importen ​
inn [45]
Where’s the picture?
5 0
3 years ago
Need help on question 3 plz<br> URGENT HELP PLZ
Law Incorporation [45]
Alloys are the homogeneous mixture of metals and non metals.... they are used in making cars and jewellery to make them more featurable,,, means that they would possess high regidity to the destruction .... both features of metal and nonmetal
5 0
3 years ago
To understand the relation between the strength of an acid or a base and its pKa and pKb values. The degree to which a weak acid
elena-14-01-66 [18.8K]

Answer:

pKa = 3.675

Explanation:

  • pKa = - Log Ka

∴ <em>C</em> X-281 = 0.079 M

∴ pH = 2.40

let X-281 a weak acid ( HA ):

∴ HA ↔ H+ + A-

⇒ Ka = [H+] * [A-] / [HA]

mass balance:

⇒<em> C</em> HA = 0.079 M = [HA] + [A-]

⇒ [HA] = 0.079 - [A-]

charge balance:

⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water

⇒ [H+] = [A-]

∴ pH = - log [H+] = 2.40

⇒ [H+] = 3.981 E-3 M

replacing in Ka:

⇒ Ka = [H+]² / ( 0.079 - [H+] )

⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )

⇒ Ka = 2.113 E-4

⇒ pKa = - Log ( 2.113 E-4 )

⇒ pKa = 3.675

8 0
3 years ago
Which of the following is a pure substance? <br> brass<br> sodium<br> rocks<br> steel
Misha Larkins [42]
Homogeneous mixture<span>steel

</span>element<span>sodium


</span>mixture, homogeneous<span>brass



</span>
3 0
3 years ago
Read 2 more answers
1.What is the specific heat capacity of granite when 20 kg absorbs 237 000 J of heat energy, causing its temperature to increase
Natalka [10]

<u>Given</u> :

  • Amount = 20 kg
  • Heat energy absorbed = 237,000 J
  • Temperature change = 15 °C

<u>Formula applied</u> :

\boxed {Q = mc \triangle T}

  • Q = absorbed heat
  • m = mass
  • c = specific heat capacity
  • ΔT = temperature change

Let's solve for c !

⇒ 237,000 = 20 × c × 15

⇒ c = 237,000 ÷ 300

⇒ \boxed {c = 790 J kg^{-1} K^{-1}}

∴ The specific heat capacity of granite is <u>790 J kg⁻¹ K⁻¹</u>.

5 0
1 year ago
Other questions:
  • If the pOH of vinegar is 9.45, what is its [OH− ]?
    11·2 answers
  • All reactions involving a change in temperature are exothermic.<br> a. True<br> b. False
    12·1 answer
  • The molar solubility for baco3 is 9.0 x 10-5 m at 25 degrees
    10·1 answer
  • When a solid compound is formed from chemicals which are in solution, it is called a?
    11·2 answers
  • Organic acids and bases in their ___________ form are soluble in organic solvents, but the corresponding _________ are more wate
    5·1 answer
  • Which of the following statements about material bonding is correct? C O a. Ionic bonds are formed by the sharing of valence ele
    9·1 answer
  • Referring to an activity series, which of the following combinations of reactants would not produce a successful single-replacem
    15·2 answers
  • How many grams of BF3 would you weigh out to make the following solution: 90.0 mL of 1.20 M BF3?
    15·1 answer
  • Why do scientists need a universal system to classify organisms?
    15·1 answer
  • . Which law of motion relates the action of a stretched rubber band
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!