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
Olin [163]
4 years ago
6

NEED HELP! An experiment _____. must always be done in a laboratory is best done if only one variable is tested for at a time ca

n be done only by direct observation must always be done in the field
Chemistry
1 answer:
hichkok12 [17]4 years ago
6 0

Answer:

Chemically

in chemistry

You might be interested in
How does gas chromatography separate substances in a mixture of compounds?
romanna [79]
Chromatography separates things according to their weight.
4 0
3 years ago
Denise heard that little children will pick food based on color. So she offered 100 kindergarteners colored mashed potatoes for
Dvinal [7]

Answer:

I think the answer is B. the number of students choosing each color.

Explanation:

7 0
2 years ago
The first-order decay of radon has a half-life of 3.823 days. How many grams of radon decomposes after 5.55 days if the sample i
Leni [432]

Answer:

The mass of radon that decompose = 63. 4 g

Explanation:

R.R = P.E/(2ᵇ/ⁿ)

Where R.R = radioactive remain, P.E = parent element, b = Time, n = half life.

Where P.E = 100 g , b = 5.55 days, n = 3.823 days.

∴ R.R = 100/2^{5.55/3.823}

  R.R = 100/2^{1.45}

  R.R = 100/2.73

  R.R = 36.63 g.

The mass of radon that decompose = Initial mass of radon - Remaining mass of radon after radioactivity.

Mass of radon that decompose = 100 - 36.63

= 63.37 ≈ 63.4 g

The mass of radon that decompose = 63. 4 g

8 0
3 years ago
A supposedly silver crown is tested to determine its density. it displaces 10.7 ml of water and has a mass of 112 g. part a coul
Anni [7]

The volume of water displace by crown is 10.7 mL. This will be equal to the volume of crown. Mass of crown is 112 g.

Density of a substance is defined as mass of substance per unit volume. It is mathematically represented as follows:

d=\frac{m}{V}

Putting the values,

d=\frac{112 g}{10.7 mL}=10.46 g/mL

The theoretical value of density of silver is 10.5 g/cm^{3} also, 1 mL is equal to 1 cm^{3} thus, density will be 10.5 g/mL.

This is approximately equal to the calculated value thus, the crown is made up of silver.


4 0
4 years ago
What's the balanced equation for magnesium and hydrochloric acid?
Roman55 [17]
Mg + 2 HCl ------> MgCl₂ +H₂O
6 0
4 years ago
Other questions:
  • Part b if you had a high-energy xenon particle beam and wanted to make gold, what element would you bombard? ? +143 54xe→197 79a
    7·1 answer
  • Which scientist invented a model of the atom that most closely resembles the modern electron cloud model?
    15·1 answer
  • UTILUCU.
    11·1 answer
  • What is the molar mass of 1-butene if 5.38 × 1016 molecules of 1-butene weigh 5.00 μg?
    13·1 answer
  • A precipitate forms when mixing solutions of sodium fluoride (NaF) and lead II nitrate (Pb(NO3)2). Complete and balance the net
    13·1 answer
  • If 0.220 mol of solid CaCO3 and 670 mL of 0.433 M aqueous H2SO4 are reacted stoichiometrically according to the balanced equatio
    9·1 answer
  • A chemist adds 0.50 mol acetic acid (CH3CO2H) to a solution. What else should be added to maximize the buffering effect?
    10·2 answers
  • Ammonium ion (NH4+) reacts with nitrite ion (NO2–) to yield nitrogen gas and liquid water. The following initial rates of reacti
    8·1 answer
  • Please don’t send me bad links !
    11·1 answer
  • What are the two different types of Barometers?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!