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
Ugo [173]
3 years ago
6

On the periodic table, calcium is in group 2. What is true about calcium?

Chemistry
1 answer:
Ray Of Light [21]3 years ago
6 0

Answer:

Explanation:

Calcium is all around us. The average human contains approximately 1kg of calcium, of which 99% is stored in our bones. It is the 5th most abundant element in the earth's crust, occurring widely as calcium carbonate which is more commonly known as limestone. It is also the fifth most abundant dissolved ion in seawater.

You might be interested in
Consider the reaction.
Alekssandra [29.7K]

Answer:The correct answer is option C.

Explanation:

N_2(g)+3H_2(g)\rightarrow 2NH_3(g)

At STP, 1 mol of gas occupies 22.4 L of volume

So, 100.0 L volume of NH_3will be occupied by :

\frac{1}{22.4 L}\times 100.0 L=4.4642 moles

According to reaction 2 moles NH_3 are obtained from 1 mole of N_2.

Then,4.4642 moles of NH_3 will be obtained from :

\frac{1}{2}\times 4.4642 that is 2.2321 moles of N_2

Mass of N_2 gas:

Moles of N_2 gas  Molar mass of N_2 gas:

2.2321 mol\times 28 g/mol=62.4988\approx 62.50 g

Hence, the correct answer is option C.

4 0
3 years ago
Read 2 more answers
Calculate the heat change in calories for melting 65 g of ice at 0 ∘c.
Genrish500 [490]

When ice melts, the physicals state changes from solid to liquid. The energy or the heat required (q) required to change a unit mass (m) of a substance from solid to liquid is known as the enthalpy or heat of fusion (ΔHf). The variables; q, m and ΔHf are related as:

q = m * ΔHf

the mass of ice m = 65 g

the heat of fusion of water at 0C = ΔHf = 334 J/g

Therefore: q = 65 g * 334 J/g = 21710 J

Now:

4.184 J = 1 cal

which implies that: 21710 J = 1 cal * 21710 J/4.184 J = 5188.8 cal

Hence the heat required is 5188.8 cal or 5.2 Kcal (approx)

5 0
3 years ago
Which of the following are considered pure substances?
Helen [10]
B.Elements

Explanation: they cannot be separated
8 0
3 years ago
Someone help me out with this brain pop ⚠️
erik [133]
The answer is b because if you’re fan is blowing and you spend it the opposite way, the air will be cooler
6 0
2 years ago
Can visible light cause damage that leads to skin cancer
11111nata11111 [884]

Visible and infrared light do not cause sunburn and they are not known to directly be a skin cancer risk.

7 0
2 years ago
Other questions:
  • What is the atomic radi for Cs and Cs+1​
    6·1 answer
  • If you started with 35.0 grams of H2S and 40.0 grams of O2, how many grams of S8 would be produced, assuming 95 % yield? 8H2S(g)
    14·1 answer
  • Help with question 20
    6·1 answer
  • 7.95 x 1022<br> 6.02 x 1023
    9·1 answer
  • What is the temperature if 2L of 3moles HCl react with 2atm?
    8·1 answer
  • Which part of John Dalton’s theory was disproved by J.J. Thomson’s cathode-ray tube experiments?(1 point)
    14·1 answer
  • What is the difference between physics and chemistry laboratory (4)
    15·2 answers
  • One of the advantages of nylon over rayon is that nylon:
    12·1 answer
  • if 3.95 mol of an ideal gas has a pressure of 2.33 atm and a volume of 60.87 l, what is the temperature of the sample in degrees
    10·1 answer
  • What mass of H atoms is contained in 50.7 g<br> of NH3?<br> Answer in units of g.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!