Chem final

According to the modern model of the atom, the nucleus is surrounded by one or more

• electrons

• protons

• neutrons

• positrons

Tags

NGSS.MS-PS1-1

All phosphorous atoms have the same

• atomic number

• mass number

• number of neutron plus protons

• number of neutrons plus electrons

At STP, which is a good conductor of electricity?

• chlorine

• iodine

• silver

• sulfur

Which quantity is equal to one mole of Au?

• the atomic mass in grams

• the atomic number in grams

• the mass of the neutrons in grams

• the number of neutrons in grams

Tags

NGSS.HS-PS1-7

Which lists three types of chemical reactions?

• solidification, single replacement, decomposition

• single replacement, decomposition, synthesis

• decomposition, synthesis, solidification

• synthesis, solidification, single replacement

 $CH_{4_{\ }}\ +\ 2O_2\ ->\ \ CO_2\ +\ 2H_2O$  Given this balanced reaction, what is the mole ratio of oxygen to methane?

• 1 gram of oxygen: 2 grams of methane

• 2 grams of oxygen: 1 gram of methane

• 1 mole of oxygen: 2 mole of methane

• 2 moles of oxygen: 1 mole of methane

See the picture. Which two models can be classified as elements?

• I and II

• I and IV

• II and III

• II and IV

Tags

NGSS.HS-PS1-1

After being thoroughly stirred , which solute makes a homogenous mixture at at 10⁰C in 100 g of water?

• 25 g KCl

• 25 g KNO₃

• 25 g NaCl

• 25 g NaNO₃

Tags

NGSS.HS-PS1-3

Which two compounds are electrolytes?

• KOH and HCl

• KOH and CH₃OH

• CH₃OH and HCl

• C₅H₁₂ and KOH

Tags

NGSS.HS-PS1-1

Which statement describes why CO₂ is a non polar molecule?

• Carbon and oxygen are both non metals

• carbon and oxygen have different electronegativities

• the molecule has a symmetrical charge distribution

• the molecule has asymmetrical charge distribution