answer.
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
Rzqust [24]
2 years ago
13

A balance measures mass to 0.001 g. If you determine the mass of an object that weighs about 30 g, would you record the mass as

30 g, 32 g, 32.1 g, or 32.075 g? Explain your choice by writ­ing one or two complete sentences that describe your thinking.
Chemistry
2 answers:
solong [7]2 years ago
8 0

Answer:

The mass is recorded as 32.075 g

Explanation:

"The first digit of uncertainty is taken as the last significant digit", this is the rule for significant figures in the analysis. The balance measures the mass up to three decimal places, so it makes the most sense to note the  whole figure.

Kazeer [188]2 years ago
5 0

Answer:

30g

Explanation:

The true mass of the recorded will be 30g ±0.001g. This figure means that the actual mass recorded lies somewhere between either 29.999g or 30.001g. Both figures could be rounded to two significant figures giving 30g.

Hence the answer written is correct to two significant figures considering the uncertainty in the measurement of the mass.

You might be interested in
Sodium chloride (NaCl) is the chemical name for table salt and potassium chloride (KCl) is a common salt substitute. Using the p
Vedmedyk [2.9K]
C because ion know I just guessed
3 0
2 years ago
Approximately what volume do 3.0 moles of kr gas occupy at stp? 80.0 40.0 l none of the above 20.0
podryga [215]
None of the above.
1 mole filled with gas at STP occupies
=22.4 L

∴ 3mole of kr gas at STP occupies
= 3 × 22.4
=  67.2 L
4 0
2 years ago
Read 2 more answers
The U.S. Mint produces a dollar coin called the American Silver Eagle that is made of nearly pure silver. This coin has a diamet
Rudik [331]

Answer:

The value of the silver in the coin is 35.3 $

Explanation:

First of all, let's calculate the volume of the coin.

2π . r² . thickness = volume

r = diameter/2

r = 41 mm/2 = 20.5 mm

2 . π . (20.5 mm)² .  2.5 mm = 6601 mm³

Now, this is the volume of the coin, so we must find out how many grams are on it.

6601 mm³ / 1000 = 6.60 cm³

Let's apply density.

D = Mass / volume

10.5 g/cm³ = mass /6.60 cm³

10.5 g/cm³ . 6.60 cm³ = mass

69.3 g = mass

Each gram has a cost of 0.51$

69.3 g . 0.51$ = 35.3 $

7 0
2 years ago
Suppose that the microwave radiation has a wavelength of 12.4 cm . How many photons are required to heat 255 mL of coffee from 2
vivado [14]

Answer:

Explanation:

wavelength λ = 12.4 x 10⁻² m .

energy of one photon = h c / λ

= 6.6 x 10⁻³⁴ x 3 x 10⁸ /  12.4 x 10⁻²

= 1.6 x 10⁻²⁴ J .

Let density of coffee be equal to density of water .

mass of coffee = 255 x 1 = 255 g

heat required to heat up coffee = mass x specific heat x rise in temp

= 255 x 4.18 x ( 62-25 )

= 39438.3 J  .

No of photons required = heat energy required / energy of one photon

= 39438.3 / 1.6 x 10⁻²⁴

= 24649 x 10²⁴

= 24.65 x 10²⁷ .

5 0
1 year ago
Marie discovers boxes of elements in a storage room. The boxes do not say which elements they contain, but they do have informat
Mazyrski [523]
<span>The elements in a Periodic Table are grouped according to their classifications. The major classifications are Metals, Non-metals, and Metalloids. Their level of reactivity can be gauged by simply looking at their position in the table. For Metals, their reactivity increases as you move to the left then going down. Non-metal reactivity increases as you move to the right then going up, starting at the bottom of the table.</span>
5 0
2 years ago
Read 2 more answers
Other questions:
  • HCl reacts with Barium Hydroxide to produce barium chloride and water. how many ml of a 3.00 M hydrochloric acid solution would
    10·1 answer
  • If 4.27 g sucrose (c12h22o11) are dissolved in 15.2 g water, what is the boiling point of the resulting solution? kb for water =
    8·2 answers
  • How many equivalents are in 0.60 mole of Mg2+
    7·1 answer
  • A 0.0035 M aqueous solution of a particular compound has pH = 2.46. The compound is (A) a weak base (B) a weak acid (C) a strong
    15·1 answer
  • A 1.80 g sample of barium chloride hydrate, BaCl2 ⋅ xH2O is treated with excess sulfuric acid, forming a BaSO4 precipitate which
    6·2 answers
  • What is the empirical formula of C6H18O3?
    15·1 answer
  • 1) How many aluminum atoms are there in 3.50 grams of Al2O3?
    8·1 answer
  • Increasing the concentration of a reactant speeds up a reaction.<br> True<br> False
    12·1 answer
  • If 1 mol of a pure triglyceride is hydrolyzed to give 2 mol of RCOOH, 1 mol of R'COOH, and 1 mol of glycerol, which of the follo
    5·1 answer
  • The process of water migrating from areas of low electrolyte concentration to area of high electrolyte concentration is called —
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!